OBJECTIVE To compare retrospectively the endoscopic treatment of pancreatic pseudocysts by retrograde pancreatic drainage (ERPD), cystogastrostomy (ECG) or cystoduodenostomy (ECD). METHODS Between 1987 and 1995 pancreatic pseudocysts were successfully treated endoscopically in 30 patients (13 women, 17 men; mean age 49 [18-89] years): ERPD was accomplished through papillary insertion of 5-7 F prostheses into the cysts or pancreatic duct in 9 patients; ECG achieved drainage of cysts in the body or tail of the pancreas in 15 patients, and ECD for cysts in the head of the pancreas in three. Combined ERPD and ECG was necessary in three patients. RESULTS Significant pain relief was achieved in all patients, accompanied by increased appetite and weight. Occlusion or dislocation of the prosthesis required renewed endoscopic drainage in three patients. The prostheses were removed, 2-12 months after implantation, when pain relief had occurred and clinical as well as radiological findings had become normal. Recurrence 10-22 months after removal of the drain was observed in four patients, of whom two had a successful second drainage procedure. Surgical intervention became necessary in three patients because of inadequate drainage or (one case) bleeding. CONCLUSIONS These data indicate that endoscopic drainage of pancreatic pseudocysts gives good results with a low complication rate and no deaths. The procedure is thus an alternative to the at present prevailing operative treatment.