diff --git a/app/src/components/StoriesTab/StoryTrackEditor.tsx b/app/src/components/StoriesTab/StoryTrackEditor.tsx
index ef20bf95..641ad048 100644
--- a/app/src/components/StoriesTab/StoryTrackEditor.tsx
+++ b/app/src/components/StoriesTab/StoryTrackEditor.tsx
@@ -500,7 +500,7 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
   }, [trimmingItem, trimSide, tempTrimValues, storyId, trimItem, toast]);
 
   const handleSplit = useCallback(() => {
-    if (!selectedClipId) return;
+    if (!selectedClipId || splitItem.isPending) return;
 
     const item = items.find((i) => i.id === selectedClipId);
     if (!item) return;
diff --git a/backend/services/stories.py b/backend/services/stories.py
index 611ab29d..cb7a46ef 100644
--- a/backend/services/stories.py
+++ b/backend/services/stories.py
@@ -484,13 +484,15 @@ async def split_story_item(
     Returns:
         List of two updated item details (original and new) or None if not found/invalid
     """
-    # Get the item
+    # Get the item with a row lock to prevent concurrent splits on the
+    # same clip (e.g. from rapid double-clicks racing each other).
     item = (
         db.query(DBStoryItem)
         .filter_by(
             id=item_id,
             story_id=story_id,
         )
+        .with_for_update()
         .first()
     )
     if not item: