There is considerable debate whether or not the laparoscopic technique for cholecystectomy supersedes conventional procedures in patients with pre-existing cardiopulmonary disease. Hemodynamic stress and CO2 absorption from the peritoneum can have a negative effect on intraoperative safety. On the other hand, a more rapid recovery of lung function and a shorter stay in hospital are the obvious advantages. 74 patients were investigated in our study: 54 with a low cardiopulmonary risk (group 1, ASA classes I or II) and 20 high risk patients belonging to ASA class III (group 2). Series of blood-gas samples were drawn from an arterial catheter and the respiratory parameters and blood gas values measured before and at the end of the CO2-insufflation period were compared. No dangerous rise in paCO2 or decrease in pH occurred with the ventilation method used in this study (Ti:Te = 1:1, PEEP = 5 mbar, Rf = 10/min modification of the tidal-volume according to the measured paCO2 and ventilation with an O2/air mixture). No significant changes in arterial O2 saturation compared with baseline values occurred and values remained within the physiological range. We conclude that excessive intraoperative paCO2 increase can be avoided by modification of the ventilation procedure and that laparoscopic cholecystectomy is an advantageous technique in the patient with cardiopulmonary disease.