Carcinoma of the papilla of Vater was diagnosed in 18 patients during the period 1970 to 1980. In ten patients, surgical treatment was facilitated by a preoperative diagnosis based on duodenal endoscopy, biopsy, cytology and retrograde cholangiopancreatography. Of 16 patients with apparently localised disease at laparotomy, nine had pancreatoduodenectomy (Whipple's operation), three had local resection and four had biliary bypass. Six of nine patients treated by pancreatoduodenectomy are surviving for periods ranging from one to ten years, mean four years, whereas the four patients treated by biliary bypass survived for 0 to 18 months. Tumour recurred in the region of the papilla in two of three patients treated by local resection. Carcinoma of the papilla of Vater is usually localised at the time of diagnosis and prolonged survival can be achieved by pancreatoduodenectomy.