Two cases of intussusception of the appendix simulating carcinoma of the cecum are described. Clinically, these patients may present with signs and symptoms of acute appendicitis or with intermittent crampy pain. Half the patients have accompanying ileocolic or cecocolic intussusception. intussuscepted appendices often have accompanying pathological conditions which may initiate the process by bulging into the lumen and serving as a lead point. These include mucoceles, parasites, carcinoid, carcinoma, scar nodules, papilloma, and lymphoid hyperplasia. Because of the varied signs and symptoms and the relative rarity of the condition, preoperative diagnosis is seldom made. The treatment is surgical removal of the appendix.