Purpose Afferent stimulus arising from gallbladder and its bed may elicit reflex inhibition of the diaphragm. Pulmonary function would be improved by blocking this stimulus after laparoscopic cholecystectomy. This randomized prospective study evaluated this hypothesis in patients who underwent laparoscopic cholecystectomy. Materials and methods During the study period, 30 patients who underwent laparoscopic cholecystectomy were randomly divided into three groups. Group I: Laparoscopic cholecystectomy; Group II: Laparoscopic cholecystectomy + irrigation of gallbladder bed with 20 mL 0.5% bupivacaine solution; Group III: Laparoscopic cholecystectomy + irrigation of gallbladder bed with bupivacaine + 10 mL 0.5% bupivacaine solution was given via a catheter every 6 h. Pulmonary function tests were performed on the day before the operation and in the morning of the first postoperative day. Forced vital capacity (FVC), forced expiratory volume at 1 s (FEV-1), and forced expiratory flow at 25% to75% (FEF 25-75%) were obtained. Results Postoperative FVC measured 53.3±4.5% of preoperative function for group I, 70.8±5.7% for group II, and 68.8±4.7% for group III (p<0.05). Postoperative FEV-1 measured 52.8±5.3% of preoperative function for group I, 69.7±4.9% for group II, and 70.5±5% for group III (p<0.05). Postoperative FEF 25-75% measured 61.1± 4.6% of the preoperative function for group I, 73.6±3% for group II, and 72.1±6% for group III (p<0.05). Conclusion The results from this study indicated that considerable improvement of pulmonary function was acquired by gallbladder bed irrigation with bupivacaine after laparoscopic cholecystectomy. © Springer-Verlag 2010.