Pancreas divisum is a congenital anomaly in which the ventral and dorsal pancreas drain separately into the duodenum. It is the most common congenital variant of pancreatic ductal fusion and drainage anomalies. With widespread use of endoscopic retrograde cholangiopancreatography, pancreas divisum is being detected with increasing frequency. Ten cases of pancreas divisum detected among 500 endoscopic retrograde cholangiopancreatography examinations performed between 1979 and 1985 at our institution were critically analyzed. Patients with symptomatic pancreas divisum (group 1) were typically young (mean age 29 yr), usually female, and had no history of significant alcohol abuse. Those with incidental detection of pancreas divisum (group 2) were older (mean age 62 yr), usually male with hepatobiliary disease, and had a history of significant alcohol ingestion. The radiological feature of pancreas divisum is characterized by a short (1-6 cm) and thin (2 mm diameter) pancreatic duct (duct of Wirsung) that branches off into regular arborization and drains only the posterior part of the head of the pancreas. This appearance is quite typical; however, this may be simulated by other conditions such as previous pancreatic trauma, partial pancreatectomy, or pancreatitis with irreversible damage to the duct, pseudocyst, and pancreatic carcinoma. The differentiation between true and false pancreas divisum is important because of its clinical implications.