Résumé : BACKGROUND: A prerequisite for endoscopic drainage of pancreatic fluid collections without EUS is the presence of a visible bulge in the GI wall. Our experience with endoscopic cystostomy of nonbulging pancreatic fluid collections is described. METHODS: Thirty-three patients underwent 34 endoscopic attempts at transmural drainage of nonbulging pancreatic fluid collections over a 2-year period. The etiology of the nonbulging pancreatic fluid collections was chronic pancreatitis in 26 cases and acute pancreatitis in 7. Indications for drainage included one or more of the following: abdominal pain, infection, biliary obstruction, and external fistula. The diameter of the collections ranged from 20 to 160 mm (median 52 mm). RESULTS: Thirty-two of 34 drainage attempts were successful (94%). Eighteen cystostomies were performed under fluoroscopy alone and 14 by EUS together with fluoroscopy. Procedure-related complications occurred with 3 of 34 attempts (8%). Surgery was not required for treatment of the complications and there were no deaths from the procedure. Follow-up was available for 31 patients (median 21 months, range 9 to 40 months). One nonbulging pancreatic fluid collections recurred 7 months after drainage. CONCLUSIONS: Endoscopic cystenterostomy of nonbulging pancreatic collections is feasible, and the results of the procedure are similar to those of cystenterostomy for bulging collections.