Enterocolic intussusception in adults is discussed with regard to incidence, location, pathology, diagnosis, and management and is illustrated by the case reports of six varieties. It should be emphasized that intraluminal tumors are the most common cause of intussusception in adults and that most such tumors of the colon are malignant. Early diagnosis, therefore, is very important, and sigmoidoscopy followed by a bariumenema study should be done in every case. Because of the sporadic occurrence and bizarre clinical picture of adult enterocolic intussusception, the physician should consider intussusception whenever confronted with any patient with confusing abdominal symptoms. Most intussusceptions in adults are subacute or chronic and cause only partial obstruction of the intestine.