We report a case of a 27-year-old man, status post open appendectomy as an infant, in whom the diagnosis of acute appendicitis of the appendiceal stump was made by computed tomography (CT). A coronal reformatted CT image demonstrated both the inflamed appendix and a normal terminal ileum. Although rare, stump appendicitis may present with signs and symptoms typical of acute appendicitis in patients status post appendectomy and should be considered in the differential diagnosis.