During evaluation for occult fever or nonspecific abdominal pain CT will occasionally identify inflammatory disease of the appendix as the underlying cause. In these cases CT may also provide useful information about the presence of associated mesenteric inflammation, abscess, or perforation. Five cases are presented in which CT provided clinically useful information supplementing that gained from barium studies and clinical presentation. When a periappendiceal lesion is found, the extent and nature of inflammatory changes are shown directly rather than inferentially.