Twenty-two patients with leiomyosarcoma of the rectum (n = 19) or the anus (n = 3) were treated surgically at the Mayo Clinic from 1950 through 1985. The majority of tumors occurred in men (1.4:1.0) during the sixth and seventh decades of life. Fifty-nine percent of the patients had symptoms including, most commonly, change in bowel habit, bleeding, and pain. Wide local excision was performed in 10 patients, whereas a more radical surgical procedure, including abdominoperineal resection (n = 8), pelvic exenteration (n = 2), and low anterior resection (n = 1), were performed in 11 patients. One tumor was unresectable. The overall survival until death from disease was 90% at 1 year, 74% at 5 years, and 51% at 10 years postoperatively. The percentage of patients free of disease at 1, 5, and 10 years postoperatively was 85, 62, and 40, respectively. Wide local resection was not superior to a more radical surgical approach in preventing tumor recurrence or improving survival. Lesions less than 2.5 cm and confined to the bowel wall can be treated by wide local excision, whereas larger or more extensive tumors should be treated by a more radical surgical approach.