diff --git a/gitignore_generator/tests/test_template_loader.py b/gitignore_generator/tests/test_template_loader.py
new file mode 100644
index 0000000..167a881
--- /dev/null
+++ b/gitignore_generator/tests/test_template_loader.py
@@ -0,0 +1,112 @@
+"""Tests for template loader."""
+
+import os
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from gitignore_generator.template_loader import TemplateLoader
+
+
+class TestTemplateLoader:
+    """Tests for TemplateLoader class."""
+
+    @pytest.fixture
+    def temp_template_dir(self):
+        """Create temporary template directory."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            yield Path(tmpdir)
+
+    @pytest.fixture
+    def loader_with_templates(self, temp_template_dir):
+        """Create loader with test templates."""
+        lang_dir = temp_template_dir / "languages"
+        lang_dir.mkdir()
+        ide_dir = temp_template_dir / "ides"
+        ide_dir.mkdir()
+
+        (lang_dir / "python.gitignore").write_text("# Python\n__pycache__/\n*.pyc\n")
+        (lang_dir / "javascript.gitignore").write_text("# JS\nnode_modules/\n")
+        (ide_dir / "vscode.gitignore").write_text("# VSCode\n.vscode/\n")
+
+        index = {"languages": ["python", "javascript"], "ides": ["vscode"], "custom": []}
+        (temp_template_dir / "templates.json").write_text(str(index))
+
+        loader = TemplateLoader()
+        loader._templates_index = index
+        return loader
+
+    def test_get_available_templates(self, loader_with_templates):
+        """Test getting available templates."""
+        templates = loader_with_templates.get_available_templates()
+        assert "python" in templates
+        assert "javascript" in templates
+        assert "vscode" in templates
+
+    def test_get_templates_by_category(self, loader_with_templates):
+        """Test getting templates by category."""
+        by_cat = loader_with_templates.get_templates_by_category()
+        assert "python" in by_cat["languages"]
+        assert "javascript" in by_cat["languages"]
+        assert "vscode" in by_cat["ides"]
+
+    def test_load_template(self, loader_with_templates):
+        """Test loading a template."""
+        content = loader_with_templates.load_template("python")
+        assert content is not None
+        assert "__pycache__" in content
+
+    def test_load_nonexistent_template(self, loader_with_templates):
+        """Test loading nonexistent template."""
+        content = loader_with_templates.load_template("nonexistent")
+        assert content is None
+
+    def test_template_exists(self, loader_with_templates):
+        """Test checking if template exists."""
+        assert loader_with_templates.template_exists("python")
+        assert not loader_with_templates.template_exists("nonexistent")
+
+    def test_search_templates(self, loader_with_templates):
+        """Test searching templates."""
+        results = loader_with_templates.search_templates("python")
+        assert "python" in results
+
+    def test_merge_templates(self, loader_with_templates):
+        """Test merging templates."""
+        merged = loader_with_templates.merge_templates(["python", "javascript"])
+        assert "__pycache__" in merged
+        assert "node_modules" in merged
+
+    def test_save_and_delete_custom_template(self, loader_with_templates, temp_template_dir):
+        """Test saving and deleting custom templates."""
+        loader = loader_with_templates
+        custom_dir = temp_template_dir / "custom"
+        custom_dir.mkdir()
+
+        content = "# Custom\ncustom_file.txt\n"
+        result = loader.save_custom_template("my_template", content)
+        assert result is True
+
+        loaded = loader.load_template("my_template")
+        assert loaded is not None
+        assert "custom_file.txt" in loaded
+
+        delete_result = loader.delete_custom_template("my_template")
+        assert delete_result is True
+
+        loaded_after = loader.load_template("my_template")
+        assert loaded_after is None
+
+    def test_load_template_with_category(self, loader_with_templates):
+        """Test loading template with explicit category."""
+        content = loader_with_templates.load_template("python", category="languages")
+        assert content is not None
+        assert "__pycache__" in content
+
+    def test_duplicate_removal_in_merge(self, loader_with_templates):
+        """Test that duplicates are removed when merging."""
+        merged = loader_with_templates.merge_templates(["python", "python"])
+        lines = [l for l in merged.splitlines() if l.strip() and not l.strip().startswith("#")]
+        unique_lines = set(lines)
+        assert len(lines) == len(unique_lines)