The duodenum is the second most common site of diverticula after the colon. Incidence of duodenal diverticula varies, from 1-6% on upper gastrointestinal contrast studies, 12-27% of endoscopic studies and up to 22% in postmortem analyses (Marhin and Amson, 2005). Most duodenal diverticula occur in the second or third portions of the duodenum, within 2.0 cm of the ampulla of Vater (Jayaraman et al., 2001). Symptomatic duodenal diverticula are rare, and their diagnosis is usually related to complications, which according to reports have included: common bile duct obstruction, acute or chronic recurrent pancreatitis, partial duodenal obstruction, diverticulitis, ulceration, hemorrhage, enterolith formation, malignant degeneration, and perforation (Whang et al., 1995). An exact preoperative diagnosis may be very difficult especially in patients with previous cancer surgery at this site. We present herein a patient with duodenal diverticulum (enterolith within the diverticulum) mimicking a periampullary neoplasm, who presented with obstructive jaundice.