Endoscopic drainage of pancreatic pseudocysts has been proposed for several years as an alternative to surgical treatment. We report the results of 26 endoscopic cystostomies of pancreatic pseudocysts (13 cystoduodenostomies, 13 cystogastrostomies) performed in two specialized centres, from 1985 to 1991. The patients were divided into 3 groups (I, II, III) according to the pseudocysts' clinical presentation. The opening of the collection into digestive lumen was achieved in 22 cases; there were 3 puncture failures and 1 cystostomy was not performed because of a prior haemorrhagic puncture. Pain relief was obtained rapidly after cystodigestive drainage in 13 out of the 14 symptomatic patients. Three complications required surgery: 1 bleeding after cystoduodenostomy, 1 perforation and 1 peritonitis after cystogastrostomies. Two of them occurred after recutting a cystostomy. Two pseudocyst surinfections healed with antibiotic therapy. No deaths occurred due to the procedure. Among the 18 long-term followed-up patients (average = 33 months), 4 required surgery for persistence or relapse of pseudocysts. The results were excellent for the 14 other patients without any difference between cystoduodenostomies and cystogastrostomies, neither between the I, II and III groups. Each of the 5 cases with a digestive lumen-pseudocyst cavity thickness above 1 cm (measured on 20 CT scans) failed: 1 puncture failure, 3 complications, 1 relapse.