A rare case of adenocarcinoma of the duodenal bulb, arising from adenoma and submitted to Whipple's procedure is presented. A diagnostic delay of about 3 months, according to literature is observed. This delay is generally due to the low incidence of the illness, aspecific symptoms and frequent endoscopic and radiologic false negative, most of all in lesions of the third and fourth duodenal portions. Diagnostic tools for these duodenal tumors are endoscopy and upper gastrointestinal barium studies (UGI). CT is useful to determine preoperatively the stage of the illness and can occasionally show the primary duodenal lesion, as in this case. Surgical approach is still controversial, except in lesions of the second duodenal portion, where Whipple operation is the procedure of choice, if the tumor is resectable, of course. In the other duodenal portions some authors suggest segmental duodenal resections instead of Whipple's procedure.