To determine the potential benefit of incentive spirometry, which has been advocated to prevent pulmonary complications after upper-abdominal surgery, we compared a group of patients receiving incentive spirometry to another group receiving no specialized postoperative respiratory care. Forty patients in the American Society of Anesthesiologists' class 1 and 2 who were undergoing cholecystectomy (through right subcostal incision) were included in the study and were randomly allocated to one of the two groups. Patients receiving incentive spirometry were encouraged by a specialized respiratory physiotherapist to breathe deeply for five minutes hourly, 12 times daily, for three postoperative days. No statistically significant difference between the two groups was found in the radiologic evidence of postoperative pulmonary complications, arterial oxygen pressure, spirometric measurement, and clinical evaluation at the second or fourth postoperative day (or both). In particular, deterioration on the chest x-ray film at the fourth postoperative day was observed in eight of 20 patients in the group receiving incentive spirometry and in six of 20 in the control group. Our study confirms the postoperative deterioration of respiratory function after upper-abdominal surgery and demonstrates the lack of therapeutic values of incentive spirometry in these patients at low risk for pulmonary complications.