BACKGROUND: We studied the effects of intraperitoneal CO2 insufflation and/or the reversed Trendelenburg position on airway pressure and compliance of the total respiratory system. METHODS: We selected and randomly allocated eighty adults to a control group C or laparoscopy group L. Without premedication, propofol and vecuronium were injected for anesthesia. In the supine position we checked peak and plateau airway pressures, and calculated the dynamic and static compliance of the total respiratory system. We only used 10o reverse Trendelenburg position in group C, and used both 10o reverse Trendelenburg position and abdominal CO2 insufflation in group L. Afterwards, we checked airway pressure and compliance and compared them between groups. RESULTS: In group C, there was no change in airway pressure and compliance. But in group L, peak airway pressure (13.9 +/- 2.4 vs 21.0 +/- 3.3 cmH2O) and plateau airway pressure (11.7 +/- 2.1 vs 18.9 +/- 3.2 cmH2O) were increased and dynamic compliance (47.7 +/- 9.1 vs 30.6 +/- 5.9 ml/cmH2O) and static compliance (58.4 +/- 12.4 vs 13.1 +/- 7.3 ml/cmH2O) of the total respiratory system were decreased. CONCLUSION: In a laparoscopic cholecystectomy, intraabdominal insufflation of CO2 raises airway pressure and reduces compliance of the total respiratory system. Reverse Trendelenburg position itself does not affect airway pressure and compliance.