We report four patients with pneumothorax as a complication of ERCP with sphincterotomy. With conservative treatment all patients recovered. Previously, 16 comparable cases have been reported in the literature. The main risk factor for this rare complication seems (pre-cut) sphincterotomy. Pneumothorax is usually right-sided or bilateral and accompanied by pneumomediastinum, pneumoretroperitoneum and subcutaneous emphysema. The prognosis seems favourable with a non-surgical approach including intravenous antibiotics, fasting and when indicated chest tube drainage.