OBJECTIVE To study the efficacy, safety and timing of endoscopic retrograde cholangiography (ERC) and sphincterotomy in patients with acute gallstone pancreatitis. METHODS Open study in Tampere University Hospital, Finland. METHODS 45 consecutive patients with acute gallstone pancreatitis who underwent ERC, with or without sphincterotomy. METHODS The results of early, compared with late, ERC with or without sphincterotomy. RESULTS ERC was successful in all 45 patients. Ampullary impacted stone was found in eight. Common duct stones were found in 21 (47%) and sphincterotomy was successful in 19 of these (90%). Nine patients developed complications (20%), five of the nine in whom severe disease had been predicted (56%) and four of the 36 in whom mild disease had been predicted (11%, p < 0.01). Three patients required operations for necrotising pancreatitis, in two of whom sphincterotomy had failed. There was no difference in outcome between the 21 patients who had ERC with or without sphincterotomy within 72 hours (median 48 h) of the onset of symptoms and the 24 in whom it was delayed for a median of 144 hours. CONCLUSIONS ERC and sphincterotomy may be done safely as a routine in patients with acute gallstone pancreatitis, and delay for a median of six days (range 3-14) from the onset of symptoms did not seem to affect the outcome in our patients.