diff --git a/src/basic_memory/mcp/tools/write_note.py b/src/basic_memory/mcp/tools/write_note.py
index 479595ef..5961c36f 100644
--- a/src/basic_memory/mcp/tools/write_note.py
+++ b/src/basic_memory/mcp/tools/write_note.py
@@ -63,7 +63,8 @@ async def write_note(
         title: The title of the note
         content: Markdown content for the note, can include observations and relations
         folder: Folder path relative to project root where the file should be saved.
-                Use forward slashes (/) as separators. Examples: "notes", "projects/2025", "research/ml"
+                Use forward slashes (/) as separators. Use "/" or "" to write to project root.
+                Examples: "notes", "projects/2025", "research/ml", "/" (root)
         project: Project name to write to. Optional - server will resolve using the
                 hierarchy above. If unknown, use list_memory_projects() to discover
                 available projects.
@@ -124,6 +125,10 @@ async def write_note(
     # Get and validate the project (supports optional project parameter)
     active_project = await get_active_project(client, project, context)
 
+    # Normalize "/" to empty string for root folder (must happen before validation)
+    if folder == "/":
+        folder = ""
+
     # Validate folder path to prevent path traversal attacks
     project_path = active_project.home
     if folder and not validate_project_path(folder, project_path):
diff --git a/test-int/mcp/test_write_note_integration.py b/test-int/mcp/test_write_note_integration.py
index 5ffcd0a6..88663ae7 100644
--- a/test-int/mcp/test_write_note_integration.py
+++ b/test-int/mcp/test_write_note_integration.py
@@ -397,6 +397,7 @@ async def test_write_note_file_path_os_path_join(mcp_server, test_project):
             "nested/folder/another-note",
         ),
         ("", "Root Note", "root-note.md", "root-note"),
+        ("/", "Root Slash Note", "root-slash-note.md", "root-slash-note"),
         (
             "folder with spaces",
             "Note Title",