diff --git a/tests/test_hooks.py b/tests/test_hooks.py
new file mode 100644
index 0000000..9f6016d
--- /dev/null
+++ b/tests/test_hooks.py
@@ -0,0 +1,234 @@
+"""Tests for git hooks module."""
+
+import os
+import tempfile
+from pathlib import Path
+
+from src.hooks import (
+    HookManager,
+    is_hook_mode,
+)
+
+
+class TestHookManager:
+    """Tests for HookManager class."""
+
+    def test_init_with_repo_path(self):
+        """Test initialization with repository path."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            assert manager.repo_path == Path(tmpdir)
+            assert manager.hooks_dir == Path(tmpdir) / ".git" / "hooks"
+
+    def test_get_hook_path(self):
+        """Test getting hook file path."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            expected = Path(tmpdir) / ".git" / "hooks" / "prepare-commit-msg"
+            assert manager.get_hook_path() == expected
+
+    def test_hook_exists_false_when_no_file(self):
+        """Test hook_exists returns False when no hook file."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            assert manager.hook_exists() is False
+
+    def test_hook_exists_true_when_file_exists(self):
+        """Test hook_exists returns True when hook file exists."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            hooks_dir = Path(tmpdir) / ".git" / "hooks"
+            hooks_dir.mkdir(parents=True)
+            hook_file = hooks_dir / "prepare-commit-msg"
+            hook_file.write_text("# existing hook")
+
+            assert manager.hook_exists() is True
+
+    def test_has_our_hook_false_when_no_file(self):
+        """Test has_our_hook returns False when no hook."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            assert manager.has_our_hook() is False
+
+    def test_has_our_hook_true_when_our_hook(self):
+        """Test has_our_hook returns True when our hook is installed."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            hooks_dir = Path(tmpdir) / ".git" / "hooks"
+            hooks_dir.mkdir(parents=True)
+            hook_file = hooks_dir / "prepare-commit-msg"
+            hook_file.write_text("# commit-gen hook")
+
+            assert manager.has_our_hook() is True
+
+    def test_has_our_hook_false_when_other_hook(self):
+        """Test has_our_hook returns False for other hooks."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            hooks_dir = Path(tmpdir) / ".git" / "hooks"
+            hooks_dir.mkdir(parents=True)
+            hook_file = hooks_dir / "prepare-commit-msg"
+            hook_file.write_text("# other hook")
+
+            assert manager.has_our_hook() is False
+
+    def test_backup_existing_hook(self):
+        """Test backing up existing hook."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            hooks_dir = Path(tmpdir) / ".git" / "hooks"
+            hooks_dir.mkdir(parents=True)
+            hook_file = hooks_dir / "prepare-commit-msg"
+            hook_file.write_text("# existing hook")
+
+            backup = manager.backup_existing_hook()
+
+            assert backup is not None
+            assert backup.exists()
+            assert backup.read_text() == "# existing hook"
+
+    def test_backup_existing_hook_no_file(self):
+        """Test backup returns None when no file."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            backup = manager.backup_existing_hook()
+            assert backup is None
+
+    def test_install_hook_success(self):
+        """Test successful hook installation."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            hooks_dir = Path(tmpdir) / ".git" / "hooks"
+            hooks_dir.mkdir(parents=True)
+
+            result = manager.install_hook()
+
+            assert result.success is True
+            assert manager.has_our_hook() is True
+
+    def test_install_hook_creates_executable(self):
+        """Test installed hook is executable."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            hooks_dir = Path(tmpdir) / ".git" / "hooks"
+            hooks_dir.mkdir(parents=True)
+
+            manager.install_hook()
+
+            hook_file = manager.get_hook_path()
+            mode = os.stat(hook_file).st_mode
+            assert mode & 0o111
+
+    def test_install_hook_backs_up_existing(self):
+        """Test hook installation backs up existing hook."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            hooks_dir = Path(tmpdir) / ".git" / "hooks"
+            hooks_dir.mkdir(parents=True)
+            hook_file = hooks_dir / "prepare-commit-msg"
+            hook_file.write_text("# existing hook")
+
+            result = manager.install_hook()
+
+            assert result.success is True
+            assert result.backup_path is not None
+
+    def test_install_hook_no_backup_when_our_hook(self):
+        """Test no backup when reinstalling our hook."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            hooks_dir = Path(tmpdir) / ".git" / "hooks"
+            hooks_dir.mkdir(parents=True)
+            hook_file = hooks_dir / "prepare-commit-msg"
+            hook_file.write_text("# commit-gen hook")
+
+            result = manager.install_hook()
+
+            assert result.success is True
+            assert result.backup_path is None
+
+    def test_install_hook_no_hooks_dir(self):
+        """Test install fails when .git/hooks doesn't exist."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+
+            result = manager.install_hook()
+
+            assert result.success is False
+            assert "not found" in result.message
+
+    def test_uninstall_hook_success(self):
+        """Test successful hook uninstallation."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            hooks_dir = Path(tmpdir) / ".git" / "hooks"
+            hooks_dir.mkdir(parents=True)
+            hook_file = hooks_dir / "prepare-commit-msg"
+            hook_file.write_text("# commit-gen hook")
+
+            result = manager.uninstall_hook()
+
+            assert result.success is True
+            assert not manager.has_our_hook()
+
+    def test_uninstall_hook_no_our_hook(self):
+        """Test uninstall fails when our hook isn't installed."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            hooks_dir = Path(tmpdir) / ".git" / "hooks"
+            hooks_dir.mkdir(parents=True)
+            hook_file = hooks_dir / "prepare-commit-msg"
+            hook_file.write_text("# other hook")
+
+            result = manager.uninstall_hook()
+
+            assert result.success is False
+
+    def test_uninstall_hook_no_file(self):
+        """Test uninstall fails when no hook file."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+
+            result = manager.uninstall_hook()
+
+            assert result.success is False
+
+    def test_restore_hook_success(self):
+        """Test restoring backed up hook."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+            hooks_dir = Path(tmpdir) / ".git" / "hooks"
+            hooks_dir.mkdir(parents=True)
+            hook_file = hooks_dir / "prepare-commit-msg"
+            backup_file = hooks_dir / "prepare-commit-msg.backup"
+            backup_file.write_text("# original hook")
+
+            result = manager.restore_hook()
+
+            assert result.success is True
+            assert hook_file.exists()
+            assert hook_file.read_text() == "# original hook"
+
+    def test_restore_hook_no_backup(self):
+        """Test restore fails when no backup exists."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            manager = HookManager(tmpdir)
+
+            result = manager.restore_hook()
+
+            assert result.success is False
+
+
+class TestIsHookMode:
+    """Tests for is_hook_mode function."""
+
+    def test_hook_mode_true(self):
+        """Test detecting hook mode."""
+        assert is_hook_mode(["hook"]) is True
+        assert is_hook_mode(["hook", "msgfile", "source"]) is True
+
+    def test_hook_mode_false(self):
+        """Test not hook mode."""
+        assert is_hook_mode([]) is False
+        assert is_hook_mode(["generate"]) is False
+        assert is_hook_mode(["--help"]) is False