A patient with a carcinoid of the ampulla of Vater presented with jaundice, generalized pruritus and a palpable gallbladder. Percutaneous intrahepatic cholangiogram showed a small mass of the ampulla of Vater with intraluminal protrusion of the common bile duct. A pancreatico-duodenectomy was performed. Microscopically, the lesion was composed of solid nests of large cells with foamy cytoplasm which did not stain for mucin and were argyrophil and argentaffin negative. Ultrastructurally, tumor cells contained dense-core granules and whorls of microfilaments. Immunoperoxidase staining demonstrated neuron-specific enolase in tumor cells; however, there was no staining for immunoactive adrenocorticotropic hormone, bombesin, gastrin, somatostatin, calcitonin, glucagon, insulin, parathormone or carcinoembryonic antigen. There was no evidence of metastases to regional lymph nodes and the patient has no evidence of recurrence 18 months later.