In this prospective, randomized study, we compared 42 patients undergoing laparoscopic cholecystectomy and 40 undergoing open cholecystectomy to determine if laparoscopic cholecystectomy results in less respiratory impairment and fewer respiratory complications. Pulmonary function tests, arterial blood-gas analysis and chest radiographs were obtained in both groups before operation and on the second day after operation. Postoperative pain scores and analgesic requirements were also recorded. After operation, a significant reduction in total lung capacity, functional residual capacity (FRC), forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and mid-expiratory flow (FEF25-75%) occurred after both laparoscopic and open cholecystectomy. The reductions in FRC, FEV1, FVC and FEF25-75% were smaller after laparoscopic (7%, 22%, 19% and 23%, respectively) than after open (21%, 38%, 32% and 34%, respectively) cholecystectomy. Laparoscopic cholecystectomy was also associated with a significantly lower incidence (28.6% vs 62.5%) and less severe atelectasis, better oxygenation and reduced postoperative pain and analgesia use compared with open cholecystectomy. We conclude that postoperative pulmonary function was impaired less after laparoscopic than after open cholecystectomy.