Background:  The role of pancreas divisum in chronic pancreatitis is controversial. Ductal changes limited to the pancreatic ventral duct (isolated ventral pancreatitis) have only been described as isolated case reports. Methods:  In a cohort of 542 patients with chronic pancreatitis we determined the frequency of ventral chronic pancreatitis among patients with pancreas divisum and analyzed the clinical presentation of 10 patients with isolated ventral alcohol-induced pancreatitis compared with 10 patients with isolated dorsal alcohol-induced pancreatitis and 30 patients with chronic pancreatitis and without pancreas divisum. Magnetic resonance pancreatography under secretin stimulation was used to evaluate the status of the dorsal pancreatic duct in some patients during follow-up. Results:  We identified 62 (11.4%) patients with pancreas divisum and 16 (2.9%) patients with incomplete pancreas divisum. The ventral duct was affected by chronic pancreatitis in 74% of these patients. Isolated ventral or dorsal duct alterations were identified in 14% and 26%, respectively, of patients with pancreas divisum. Patients with isolated ventral pancreatitis had pain symptoms similar to those of the two other groups but had no endocrine or exocrine insufficiency on initial presentation. After a mean follow-up of 44 months, 83% of patients studied with isolated ventral pancreatitis developed alterations of the dorsal ductal part of the gland. Conclusion:  We conclude that isolated ventral alcohol-induced pancreatitis is one of the first manifestations of generalized pancreatic disease where the anatomic factor of pancreas divisum plays only a marginal role. (Gastrointest Endosc 2000;51:45-50.)