Course of the disease and microscopic work-up of the operative specimens with special consideration of morphological carcinogenesis were analysed in 72 patients with tumour of the ampulla of Vater. Mean duration since onset of symptoms was 6.6 weeks. Cardinal symptoms were jaundice, loss of weight and abdominal pain. Endoscopic-retrograde cholangio-pancreatography, computed tomography and percutaneous transhepatic cholangiography had the highest diagnostic accuracy. Resection rate of the carcinoma was 55%, hospital mortality was 6.7% for partial duodenopancreatectomy and 15.4% for palliative surgery. The mean survival rate was 20 months after partial duodenopancreatectomy and 5 months after palliative surgery. The survival rate was significantly decreased if tumour size was above 2 cm and lymph nodes were positive for tumour. In 82.8% of the examined operative specimens moderate to high-grade epithelial dysplasias were found in carcinoma-free portions of the ampulla, and in 91.4% there were adenomatous structures. It is to be assumed that carcinoma of the ampulla develops via dysplastic epithelial changes or from adenoma of the ampulla.