BACKGROUND The purpose of this study was to prospectively compare the effect of laparoscopic cholecystectomy (LC) versus open cholecystectomy (OC) on postoperative pulmonary function. METHODS Forty consecutive patients (20 in each group) who were evenly matched in terms of pulmonary risk factors were assigned to either elective LC or OC. Pulmonary function studies, oxygen saturation, and chest radiography were performed on both groups before and after the operation until baseline levels were reached. Narcotic requirements and pulmonary complications were compared. The t test, ANOVA, and chi-squared analysis were used. RESULTS Compared to the patients who underwent OC, patients who underwent LC had a significant reduction in postoperative pulmonary impairment (30% to 38%) in all areas studied including forced vital capacity; forced expiratory volume in 1 second; forced expiratory flow, mid-expiratory phase; maximum forced expiratory flow; maximum voluntary ventilation; total lung capacity; and oxygen saturation. Pulmonary function returned to baseline levels 4 to 10 days sooner after LC. Pulmonary complications including atelectasis and hypoxia were less frequent after LC. An eight-fold decrease was noted in postoperative pain medication requirement in the LC group. CONCLUSIONS Compared to OC, laparoscopic cholecystectomy results in a significantly reduced compromise in pulmonary function and narcotic requirement leading to fewer postoperative pulmonary complications. Laparoscopic cholecystectomy should be considered the procedure of choice for elective cholecystectomy.