A focal dilatation of a loop of small bowel has been identified in the left upper quadrant in a series of individuals with suspected appendicitis. Retrospective review of 100 cases of surgically proven appendicitis demonstrated this sign in 51. No previous description of this sign has been found. This finding is believed to be an early sign of appendicitis and may be a valuable adjunct in combination with a clinical history without other radiologic signs of appendicitis. The more conventional signs of appendicitis such as appendicolith and focal ileus of the terminal ileum reinforce the diagnosis.