A young woman with acute myelocytic leukemia developed acute lower gastrointestinal bleeding immediately after a first remission induction of her leukemia. After the site of bleeding was located in the descending colon, a necrotic bleeding ulcer was resected. Histologic examination of the ulcer established the diagnosis of gastrointestinal mucormycosis. Treatment with amphotericin B was administered because of the high risk of dissemination. The patient has been followed for 9 months with no evidence of relapse of infection. Survival after gastrointestinal mucormycosis in acute leukemia has not previously been reported in the English language literature. Success in managing mucormycosis depends on the adherence to the recommended principles of early aggressive diagnostic measures, excisional surgery, amphotericin B therapy, and control of the underlying predisposing condition.