diff --git a/docs/task3_status.md b/docs/task3_status.md
index d7368ee..a45cf6b 100644
--- a/docs/task3_status.md
+++ b/docs/task3_status.md
@@ -258,7 +258,7 @@ Task 3 is **95% Complete** and **Production Ready**.
 **⚠️ Documentation Remaining (5%):**
 
 -   📝 TMDB API setup guide (10 min)
--   📝 Configuration examples for README (10 min)  
+-   📝 Configuration examples for README (10 min)
 -   📝 ARCHITECTURE.md component diagram (10 min)
 
 **Optional Future Work (Not blocking):**
diff --git a/scripts/test_nfo_update.py b/scripts/test_nfo_update.py
new file mode 100644
index 0000000..af798db
--- /dev/null
+++ b/scripts/test_nfo_update.py
@@ -0,0 +1,183 @@
+"""Test script for NFOService.update_tvshow_nfo() functionality.
+
+This script tests the update functionality by:
+1. Creating a test NFO file with TMDB ID
+2. Updating it with fresh data from TMDB
+3. Verifying the update worked correctly
+"""
+
+import asyncio
+import logging
+import sys
+from pathlib import Path
+
+# Add src to path
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+from src.config.settings import settings
+from src.core.services.nfo_service import NFOService
+from src.core.services.tmdb_client import TMDBAPIError
+
+# Configure logging
+logging.basicConfig(
+    level=logging.INFO,
+    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
+)
+logger = logging.getLogger(__name__)
+
+
+async def test_update_nfo():
+    """Test NFO update functionality."""
+    
+    # Check if TMDB API key is configured
+    if not settings.tmdb_api_key:
+        logger.error("TMDB_API_KEY not configured in environment")
+        logger.error("Set TMDB_API_KEY in .env file or environment variables")
+        return False
+    
+    # Test series: Attack on Titan (TMDB ID: 1429)
+    test_serie_name = "Attack on Titan"
+    test_serie_folder = "test_update_nfo"
+    test_tmdb_id = 1429
+    
+    # Create test folder
+    test_folder = Path(settings.anime_directory) / test_serie_folder
+    test_folder.mkdir(parents=True, exist_ok=True)
+    logger.info(f"Created test folder: {test_folder}")
+    
+    # Initialize NFO service
+    nfo_service = NFOService(
+        tmdb_api_key=settings.tmdb_api_key,
+        anime_directory=settings.anime_directory,
+        image_size=settings.nfo_image_size
+    )
+    
+    try:
+        # Step 1: Create initial NFO
+        logger.info("=" * 60)
+        logger.info("STEP 1: Creating initial NFO")
+        logger.info("=" * 60)
+        
+        nfo_path = await nfo_service.create_tvshow_nfo(
+            serie_name=test_serie_name,
+            serie_folder=test_serie_folder,
+            year=2013,
+            download_poster=False,  # Skip downloads for faster testing
+            download_logo=False,
+            download_fanart=False
+        )
+        
+        logger.info(f"✓ Initial NFO created: {nfo_path}")
+        
+        # Read initial NFO content
+        initial_content = nfo_path.read_text(encoding="utf-8")
+        logger.info(f"Initial NFO size: {len(initial_content)} bytes")
+        
+        # Verify TMDB ID is in the file
+        if str(test_tmdb_id) not in initial_content:
+            logger.error(f"TMDB ID {test_tmdb_id} not found in NFO!")
+            return False
+        logger.info(f"✓ TMDB ID {test_tmdb_id} found in NFO")
+        
+        # Step 2: Update the NFO
+        logger.info("")
+        logger.info("=" * 60)
+        logger.info("STEP 2: Updating NFO with fresh data")
+        logger.info("=" * 60)
+        
+        updated_path = await nfo_service.update_tvshow_nfo(
+            serie_folder=test_serie_folder,
+            download_media=False  # Skip downloads
+        )
+        
+        logger.info(f"✓ NFO updated: {updated_path}")
+        
+        # Read updated content
+        updated_content = updated_path.read_text(encoding="utf-8")
+        logger.info(f"Updated NFO size: {len(updated_content)} bytes")
+        
+        # Verify TMDB ID is still in the file
+        if str(test_tmdb_id) not in updated_content:
+            logger.error(f"TMDB ID {test_tmdb_id} not found after update!")
+            return False
+        logger.info(f"✓ TMDB ID {test_tmdb_id} still present after update")
+        
+        # Step 3: Test update on non-existent NFO (should fail)
+        logger.info("")
+        logger.info("=" * 60)
+        logger.info("STEP 3: Testing error handling")
+        logger.info("=" * 60)
+        
+        try:
+            await nfo_service.update_tvshow_nfo(
+                serie_folder="non_existent_folder",
+                download_media=False
+            )
+            logger.error("✗ Should have raised FileNotFoundError!")
+            return False
+        except FileNotFoundError as e:
+            logger.info(f"✓ Correctly raised FileNotFoundError: {e}")
+        
+        # Step 4: Test update on NFO without TMDB ID
+        logger.info("")
+        logger.info("STEP 4: Testing NFO without TMDB ID")
+        
+        # Create a minimal NFO without TMDB ID
+        no_id_folder = test_folder.parent / "test_no_tmdb_id"
+        no_id_folder.mkdir(parents=True, exist_ok=True)
+        no_id_nfo = no_id_folder / "tvshow.nfo"
+        no_id_nfo.write_text(
+            '<?xml version="1.0" encoding="UTF-8"?>\n'
+            '<tvshow>\n'
+            '  <title>Test Show</title>\n'
+            '</tvshow>',
+            encoding="utf-8"
+        )
+        
+        try:
+            await nfo_service.update_tvshow_nfo(
+                serie_folder="test_no_tmdb_id",
+                download_media=False
+            )
+            logger.error("✗ Should have raised TMDBAPIError!")
+            return False
+        except TMDBAPIError as e:
+            logger.info(f"✓ Correctly raised TMDBAPIError: {e}")
+        
+        logger.info("")
+        logger.info("=" * 60)
+        logger.info("✓ ALL TESTS PASSED")
+        logger.info("=" * 60)
+        return True
+        
+    except Exception as e:
+        logger.error(f"✗ Test failed with error: {e}", exc_info=True)
+        return False
+    
+    finally:
+        await nfo_service.close()
+        
+        # Cleanup test folders
+        logger.info("\nCleaning up test folders...")
+        import shutil
+        try:
+            if test_folder.exists():
+                shutil.rmtree(test_folder)
+                logger.info(f"Removed: {test_folder}")
+            
+            no_id_folder = test_folder.parent / "test_no_tmdb_id"
+            if no_id_folder.exists():
+                shutil.rmtree(no_id_folder)
+                logger.info(f"Removed: {no_id_folder}")
+        except Exception as e:
+            logger.warning(f"Cleanup error: {e}")
+
+
+async def main():
+    """Main entry point."""
+    success = await test_update_nfo()
+    sys.exit(0 if success else 1)
+
+
+if __name__ == "__main__":
+    asyncio.run(main())
diff --git a/src/core/services/nfo_service.py b/src/core/services/nfo_service.py
index 42501af..9d8173b 100644
--- a/src/core/services/nfo_service.py
+++ b/src/core/services/nfo_service.py
@@ -12,6 +12,8 @@ import logging
 from pathlib import Path
 from typing import Any, Dict, List, Optional
 
+from lxml import etree
+
 from src.core.entities.nfo_models import (
     ActorInfo,
     ImageInfo,
@@ -158,21 +160,76 @@ class NFOService:
             
         Raises:
             FileNotFoundError: If NFO file doesn't exist
-            TMDBAPIError: If TMDB API fails
+            TMDBAPIError: If TMDB API fails or no TMDB ID found in NFO
         """
-        nfo_path = self.anime_directory / serie_folder / "tvshow.nfo"
+        folder_path = self.anime_directory / serie_folder
+        nfo_path = folder_path / "tvshow.nfo"
         
         if not nfo_path.exists():
             raise FileNotFoundError(f"NFO file not found: {nfo_path}")
         
-        # Parse existing NFO to get TMDB ID
-        # For simplicity, we'll recreate from scratch
-        # In production, you'd parse the XML to extract the ID
-        
         logger.info(f"Updating NFO for {serie_folder}")
-        # Implementation would extract serie name and call create_tvshow_nfo
-        # This is a simplified version
-        raise NotImplementedError("Update NFO not yet implemented")
+        
+        # Parse existing NFO to extract TMDB ID
+        try:
+            tree = etree.parse(str(nfo_path))
+            root = tree.getroot()
+            
+            # Try to find TMDB ID from uniqueid elements
+            tmdb_id = None
+            for uniqueid in root.findall(".//uniqueid"):
+                if uniqueid.get("type") == "tmdb":
+                    tmdb_id = int(uniqueid.text)
+                    break
+            
+            # Fallback: check for tmdbid element
+            if tmdb_id is None:
+                tmdbid_elem = root.find(".//tmdbid")
+                if tmdbid_elem is not None and tmdbid_elem.text:
+                    tmdb_id = int(tmdbid_elem.text)
+            
+            if tmdb_id is None:
+                raise TMDBAPIError(
+                    f"No TMDB ID found in existing NFO. "
+                    f"Delete the NFO and create a new one instead."
+                )
+            
+            logger.debug(f"Found TMDB ID: {tmdb_id}")
+            
+        except etree.XMLSyntaxError as e:
+            raise TMDBAPIError(f"Invalid XML in NFO file: {e}")
+        except ValueError as e:
+            raise TMDBAPIError(f"Invalid TMDB ID format in NFO: {e}")
+        
+        # Fetch fresh data from TMDB
+        async with self.tmdb_client:
+            logger.debug(f"Fetching fresh data for TMDB ID: {tmdb_id}")
+            details = await self.tmdb_client.get_tv_show_details(
+                tmdb_id,
+                append_to_response="credits,external_ids,images"
+            )
+            
+            # Convert TMDB data to TVShowNFO model
+            nfo_model = self._tmdb_to_nfo_model(details)
+            
+            # Generate XML
+            nfo_xml = generate_tvshow_nfo(nfo_model)
+            
+            # Save updated NFO file
+            nfo_path.write_text(nfo_xml, encoding="utf-8")
+            logger.info(f"Updated NFO: {nfo_path}")
+            
+            # Re-download media files if requested
+            if download_media:
+                await self._download_media_files(
+                    details,
+                    folder_path,
+                    download_poster=True,
+                    download_logo=True,
+                    download_fanart=True
+                )
+            
+            return nfo_path
     
     def _find_best_match(
         self,
diff --git a/tests/unit/test_nfo_update_parsing.py b/tests/unit/test_nfo_update_parsing.py
new file mode 100644
index 0000000..d68fde2
--- /dev/null
+++ b/tests/unit/test_nfo_update_parsing.py
@@ -0,0 +1,178 @@
+"""Unit test for NFOService.update_tvshow_nfo() - tests XML parsing logic."""
+
+import asyncio
+from pathlib import Path
+import tempfile
+import shutil
+
+from lxml import etree
+import pytest
+
+from src.core.services.nfo_service import NFOService
+from src.core.services.tmdb_client import TMDBAPIError
+
+
+def create_sample_nfo(tmdb_id: int = 1429) -> str:
+    """Create a sample NFO XML with TMDB ID."""
+    return f'''<?xml version="1.0" encoding="UTF-8"?>
+<tvshow>
+    <title>Attack on Titan</title>
+    <originaltitle>Shingeki no Kyojin</originaltitle>
+    <year>2013</year>
+    <plot>Several hundred years ago, humans were nearly exterminated by Titans.</plot>
+    <uniqueid type="tmdb" default="false">{tmdb_id}</uniqueid>
+    <uniqueid type="tvdb" default="true">267440</uniqueid>
+    <tmdbid>{tmdb_id}</tmdbid>
+    <tvdbid>267440</tvdbid>
+</tvshow>'''
+
+
+def test_parse_nfo_with_uniqueid():
+    """Test parsing NFO with uniqueid elements."""
+    # Create temporary directory structure
+    temp_dir = Path(tempfile.mkdtemp())
+    serie_folder = temp_dir / "test_series"
+    serie_folder.mkdir()
+    nfo_path = serie_folder / "tvshow.nfo"
+    
+    try:
+        # Write sample NFO
+        nfo_path.write_text(create_sample_nfo(1429), encoding="utf-8")
+        
+        # Parse it (same logic as in update_tvshow_nfo)
+        tree = etree.parse(str(nfo_path))
+        root = tree.getroot()
+        
+        # Extract TMDB ID
+        tmdb_id = None
+        for uniqueid in root.findall(".//uniqueid"):
+            if uniqueid.get("type") == "tmdb":
+                tmdb_id = int(uniqueid.text)
+                break
+        
+        assert tmdb_id == 1429, f"Expected TMDB ID 1429, got {tmdb_id}"
+        print(f"✓ Successfully parsed TMDB ID from uniqueid: {tmdb_id}")
+        
+    finally:
+        shutil.rmtree(temp_dir)
+
+
+def test_parse_nfo_with_tmdbid_element():
+    """Test parsing NFO with tmdbid element (fallback)."""
+    # Create NFO without uniqueid but with tmdbid element
+    nfo_content = '''<?xml version="1.0" encoding="UTF-8"?>
+<tvshow>
+    <title>Test Show</title>
+    <tmdbid>12345</tmdbid>
+</tvshow>'''
+    
+    temp_dir = Path(tempfile.mkdtemp())
+    serie_folder = temp_dir / "test_series"
+    serie_folder.mkdir()
+    nfo_path = serie_folder / "tvshow.nfo"
+    
+    try:
+        nfo_path.write_text(nfo_content, encoding="utf-8")
+        
+        # Parse it
+        tree = etree.parse(str(nfo_path))
+        root = tree.getroot()
+        
+        # Try uniqueid first (should fail)
+        tmdb_id = None
+        for uniqueid in root.findall(".//uniqueid"):
+            if uniqueid.get("type") == "tmdb":
+                tmdb_id = int(uniqueid.text)
+                break
+        
+        # Fallback to tmdbid element
+        if tmdb_id is None:
+            tmdbid_elem = root.find(".//tmdbid")
+            if tmdbid_elem is not None and tmdbid_elem.text:
+                tmdb_id = int(tmdbid_elem.text)
+        
+        assert tmdb_id == 12345, f"Expected TMDB ID 12345, got {tmdb_id}"
+        print(f"✓ Successfully parsed TMDB ID from tmdbid element: {tmdb_id}")
+        
+    finally:
+        shutil.rmtree(temp_dir)
+
+
+def test_parse_nfo_without_tmdb_id():
+    """Test parsing NFO without TMDB ID raises appropriate error."""
+    # Create NFO without any TMDB ID
+    nfo_content = '''<?xml version="1.0" encoding="UTF-8"?>
+<tvshow>
+    <title>Test Show</title>
+</tvshow>'''
+    
+    temp_dir = Path(tempfile.mkdtemp())
+    serie_folder = temp_dir / "test_series"
+    serie_folder.mkdir()
+    nfo_path = serie_folder / "tvshow.nfo"
+    
+    try:
+        nfo_path.write_text(nfo_content, encoding="utf-8")
+        
+        # Parse it
+        tree = etree.parse(str(nfo_path))
+        root = tree.getroot()
+        
+        # Try to extract TMDB ID
+        tmdb_id = None
+        for uniqueid in root.findall(".//uniqueid"):
+            if uniqueid.get("type") == "tmdb":
+                tmdb_id = int(uniqueid.text)
+                break
+        
+        if tmdb_id is None:
+            tmdbid_elem = root.find(".//tmdbid")
+            if tmdbid_elem is not None and tmdbid_elem.text:
+                tmdb_id = int(tmdbid_elem.text)
+        
+        assert tmdb_id is None, "Should not have found TMDB ID"
+        print("✓ Correctly identified NFO without TMDB ID")
+        
+    finally:
+        shutil.rmtree(temp_dir)
+
+
+def test_parse_invalid_xml():
+    """Test parsing invalid XML raises appropriate error."""
+    nfo_content = '''<?xml version="1.0" encoding="UTF-8"?>
+<tvshow>
+    <title>Unclosed tag
+</tvshow>'''
+    
+    temp_dir = Path(tempfile.mkdtemp())
+    serie_folder = temp_dir / "test_series"
+    serie_folder.mkdir()
+    nfo_path = serie_folder / "tvshow.nfo"
+    
+    try:
+        nfo_path.write_text(nfo_content, encoding="utf-8")
+        
+        # Try to parse - should raise XMLSyntaxError
+        try:
+            tree = etree.parse(str(nfo_path))
+            assert False, "Should have raised XMLSyntaxError"
+        except etree.XMLSyntaxError:
+            print("✓ Correctly raised XMLSyntaxError for invalid XML")
+        
+    finally:
+        shutil.rmtree(temp_dir)
+
+
+if __name__ == "__main__":
+    print("Testing NFO XML parsing logic...")
+    print()
+    
+    test_parse_nfo_with_uniqueid()
+    test_parse_nfo_with_tmdbid_element()
+    test_parse_nfo_without_tmdb_id()
+    test_parse_invalid_xml()
+    
+    print()
+    print("=" * 60)
+    print("✓ ALL TESTS PASSED")
+    print("=" * 60)