A 67-year-old man was admitted to our hospital because of general fatigue and jaundice. Computed tomography, magnetic resonance imaging and endoscopic retrograde cholangiopancreatography studies revealed obstructive jaundice caused by Papilla Vater's tumor. Possible existence of malignancy required pancreatoduodenectomy with lymphnode dissection(D2), despite no definitive diagnosis was made in preoperative endoscopic biopsy. Immunohistochemical stainings of the tumor cells with anti-Chromogranin A antibody and anti-Synaptophysin antibody were both positive ; histological diagnosis from the surgically resected specimen was small-cell carcinoma (endocrine cell carcinoma). Small-cell carcinoma originated from the Ampulla of Vater is rare, and the exact definition of this disease was reorganized only a decade ago, and the therapeutic strategy is still contravertial. We report herein a case of small-cell carcinoma (endocrine cell carcinoma) originated from the Ampulla of Vater in which a radical resection was completed.