Pancreatic lipomatosis is characterized by fatty infiltration or replacement of the pancreas, and has been associated with many conditions. We recently experienced two cases of pancreatic lipomatosis in patients with pancreatic pseudocyst and a case of lipomatosis in diabetes mellitus. In these patients, abrupt obstruction of the main pancreatic duct with smooth tapering is a typical endoscopic retrograde pancreatography (ERP) finding of pancreatic lipomatosis and must be differentiated with pancreatic carcinoma.