Forty-five carcinomas of the region of the ampulla of Vater were resected at the Toronto General Hospital during a 16-year period. In 26 the presenting symptom was pain and in 32 it was jaundice. The most useful means of investigation was endoscopic retrograde cholangiopancreatography. Angiography was of value in determining resectability prior to operation, and percutaneous aspiration biopsy allowed a preoperative diagnosis in the case of large pancreatic tumours. In 39 patients who had a Whipple procedure the operative mortality was 8%. Total pancreatectomy performed in two patients and local excision of ampullary carcinoma in four patients were attended by no operative deaths. Long-term survival was best in patients with ampullary carcinomas and worst in those with pancreatic cancer.