A retrospective analysis has been made of 89 patients, who were treated for acute pancreatitis and later underwent cholecystectomy. The object was to elucidate whether cholecystectomy can be performed soon after recovery from the pancreatitis ('early operation') or must be postponed a few months ('elective operation'). While waiting for operation a quarter of the patients in the elective group had a recurrent attack of pancreatitis or acute cholecystitis. A further quarter of the patients had slight symptoms. The postoperative complications were few, their frequency being comparable in both groups. No damage resulted to the common bile duct, there was no postoperative bleeding and only one case of postoperative pancreatitis in the group of patients operated early. It is concluded that 'early operation' is to be preferred provided a firm diagnosis of gallstone disease has been made. However, the oral cholecystogram is unreliable during the first three weeks after the attack of pancreatitis. If an oral cholecystogram is performed during these weeks and shows nonvisualization of the gallbladder but no stones, a repeated examination must be performed.