We report the CT diagnosis of two cases of alimentary tract perforation caused by the ingestion of foreign bodies. The first case was a common fish bone perforation of the ileum with postoperative scar. The second case was a rare perforation caused by the impact of an uncooked rice cake on sigmoid colon diverticula. Helical CT scan clearly revealed the fish bone as a linear high-density area in the soft tissue between the right abdominal oblique muscles and ileum, and demonstrated the rice cake as high-density material in the bowel.