Background: An early decompression of the biliary tract can be useful in biliary pancreatitis. This can be accomplished with an ERCP. Aim: To analyze prospectively the outcomes of ERCP and eventual endoscopic management among patients with mild acute biliary pancreatitis with gallbladder in situ. Material and methods: We studied 90 consecutive patients aged between 15 and 92 years (71 females) with mild acute pancreatitis and gallbladder in situ, that were subjected to an ERCP and eventual sphincterotomy. Forty nine patients (54%) had jaundice and 12 (13%) had cholangitis. Results: In 67 patients (74%), ERCP detected an abnormal ampulla. The bile duct was successfully cannulated in 89 cases (99%). Of these, 42 (47%) had a dilated bile duct and 36 (40%) had choledocholithiasis. In two patients (2%) ERCP was only diagnostic. In the remaining patients, it was therapeutic. Endoscopic treatment was successful in 86 patients (99%). No complications arising from the endoscopic procedure were recorded. Follow-up was completed in 84 patients (94%). Of these, 10 (12%) were not subjected to a cholecystectomy, in eight due to a high surgical risk and in two due to refusal. In the remaining 74 patients, a cholecystectomy was performed during the same hospitalization in 57 (77%) and on a deferred basis in 17 (23%). Conclusions: In patients with mild acute biliary pancreatitis and gallbladder in situ, ERCP is a safe and effective method.