Wegener's granulomatosis is a disease characterized by necrotizing vasculitis and granulomatous inflammation. Gastrointestinal (GI) involvement is uncommon in this disorder. Only a few cases of perforation of GI tract have been reported, but vasculitis has not been demonstrated to be a cause of perforation in these cases. We report a case of Wegener's granulomatosis in which a single perforation in the terminal ileum was disclosed on laparotomy and active necrotizing vasculitis was found in the submucosal layer of the resected specimen.