Endoscopic drainage of pancreatic pseudocysts was attempted in 17 patients over an eight year period. There were nine cysts located in the head of the pancreas, six in the body and two in the tail. Endoscopic retrograde cholangiopancreatography was performed in all cases and the pancreatic duct satisfactorily opacified in 16 of the 17 patients. This study identified a communication with the pancreatic duct in seven cases. There were two cases in which multiple cysts were present; in each, one cyst was drained endoscopically and the others surgically. Endoscopic drainage of the cyst was immediately possible in 16 of 17 cases (94%). Late follow-up (mean 26 months) documented cyst disappearance in 11 cases (69%). None of the five patients with persistent cysts has required secondary surgical intervention, and the cysts are asymptomatic and stable or decreasing in size by serial scanning. There was one case (6%) in which a pseudocyst recurred following initial resolution. There were two complications (12%) requiring surgical intervention: gastrointestinal perforation with peritonitis in one patient and hemorrhage at the cyst margin from an arterial bleeder in another. There were no deaths at 30 days, but in one case a recurrent acute necrotizing pancrearitis occurred 36 days following endoscopic drainage and the patient died. This death was felt to be unrelated to the endoscopic procedure. In conclusion, internal drainage of pancreatic pseudocysts by endoscopic means can be proposed as an alternative to surgical drainage when the cyst can be identified as bulging into the stomach or duodenum. Immediate drainage is usually effective with a minimal long term recurrence rate.