SummaryThe potential advantages of pressure-controlled over volume-controlled ventilation during laparoscopic surgery have yet to be proven. We randomly assigned 42 patients with BMI < 30 kg.m )2 scheduled for laparoscopic cholecystectomy to receive either pressure-or volumecontrolled ventilation. Compared with volume-controlled ventilation, pressure-controlled ventilation resulted in a significant decrease in mean (SD) peak airway pressure at 10 min (20.4 (2.7) vs 24.0 (4.7) cmH 2 O, p = 0.004) and 30 min (20.7 (3.0) vs 23.9 (4.9) cmH 2 O, p = 0.015) and an increase in mean airway pressure at 10 min (10.5 (0.9) vs 9.6 (1.1) cmH 2 O, p = 0.007) and 30 min (10.5 (1.1) vs 9.6 (1.2) cmH 2 O, p = 0.016) after the start of surgery. Gas exchange and haemodynamic stability were similar. We conclude that pressure-controlled ventilation is a safe alternative and offers some advantages to volume-controlled ventilation during laparoscopic cholecystectomy in non-obese patients.