Uterine carcinosarcoma is a rare and rapidly fatal malignancy. The records of 49 patients with carcinosarcoma were studied; from these studies emerged a symptom complex of vaginal bleeding and abdominal or pelvic pain. Eleven patients had been previously irradiated at an average of 16.4 years before they developed uterine carcinosarcoma. Celiotomies revealed more extensive tumor than could be determined by pelvic examination under anesthesia. The majority of the patients died from local recurrence in the pelvis rather than from distant metastases. The overall 5-year survival was 6%. Celiotomies are recommended to stage carcinosarcomas and guide treatment decisions.