SummaryA typical case of islet cell tumor of the pancreas is reported. The clinical diagnosis is supported by severe hypoglycemia, obesity and increasing irritability. Blood tests confirm the high rate of the pancreatic insulin secretion. Superior mesenteric arteriography demonstrates and localizes the adenoma. Laparotomy confirms the localization. Subtotal pancreatectomy is performed and all hypoglycemic symptoms disappear immediately.Preoperative angiography and subtotal pancreatectomy are advocated to reach a 90 % successful treatment.