A 52-year-old man with a pedunculated ampullary carcinoma was referred for endosonography. Endoscopic retrograde cholangiopancreatography was unsuccessful because of pedunculation of the papilla. Endosonography revealed a superficial hypoechoic tumor limited to the mucosa, which was compatible with a T1 carcinoma according to the new (1987) Union Internationale Contre le Cancer TNM classification of the polypoid tumor. No lymph node metastases were found, the staging being T1N0. Local tumor resection was performed. Lymph node metastases were not found at surgery. Histology of the resected specimen confirmed the findings at endosonography. Follow-up endoscopy and endosonography 18 months after surgery showed no evidence of tumor recurrence or lymphadenopathy.