Comparative pulmonary function after cholecystectomy performed through Kocher's incision, a mini-incision, and laparoscopy was evaluated. Forty-five patients were randomly and prospectively divided into three groups of 15 each, depending on the surgical access employed. Forced vital capacity (FVC), forced expiratory volume at 1 second (FEV1), and forced expiratory flow at 25% to 75% (FEF25-75%) were determined 1 to 3 days before and 16 to 24 hours after cholecystectomy. The percent reduction of FVC (p = 0.0170), FEV, (p = 0.0191), and FEF25-75% (p = 0.0045) was smaller after laparoscopic cholecystectomy than after Kocher's incision cholecystectomy. The percent reduction of FVC (p = 0.0170) was smaller after mini-incision cholecystectomy than after Kocher's incision cholecystectomy. There was no difference in the FEV, (p = 0.0971) or FEF25-75% (p = 0.2058) between these two groups. FEF25-75% was significantly less impaired in the laparoscopic group than in the mini-incision group (p = 0.0327). No difference between these two groups was found in FVC (p = 0.5755) or FEV, (p = 0.3952). It is concluded that postoperative pulmonary function is less impaired after laparoscopic cholecystectomy than after either mini-incision or Kocher's incision cholecystectomy.