A 53-year-old man complaining of vertigo initially consulted a nearby hospital. While undergoing a medical examination, which included abdominal ultrasonography and a CT scan, a dilatation of the pancreatic duct was found. The patient was then admitted to our hospital for a more thorough examination. Laboratory findings revealed an elevated elastase-1 level and a DM-pattern of 75 g-OGTT. ERP showed a localized constriction in the main pancreatic duct and diffuse dilatations of the distal main duct. A cytologic examination revealed no malignant cells in the pancreatic juice. Even so, though a carcinoma was not confirmed, a pancreaticoduodenectomy was performed, since a carcinoma of the pancreas head was suspected. A histological examination of the resected specimen uncovered a nonfunctioning islet cell carcinoma, 8 mm in diameter. This case was considered fortunate, in that an early stage pancreatic cancer, adjacent to the main duct, had been detected by imaging diagnoses.