Hemodynamic measurements were performed in 10 healthy women undergoing elective laparoscopy for the investigation of infertility. A standardized anesthetic technique which included the application of positive end-expiratory pressure (PEEP), 0.49 kPa (3.7 mmHg) was utilized. The following variables were studied: cardiac output, stroke volume and left ventricular ejection time (determined non-invasively with impedance cardiography), heart rate, blood pressure, total peripheral vascular resistance and end-tidal carbon dioxide (ET-CO2). The combination of 25 degrees head-down tilt and PEEP ventilation during laparoscopy was associated with a pressure response that restored arterial pressures to essentially pre-anesthetic levels. Net cardiac effects were small. With this regime low pressure 0.7-1.1 kPa (5-8 mmHg) intra-abdominal insufflation with CO2 was associated with only minor cardiovascular changes. There were no indications that 0.49 kPa PEEP during laparoscopy produced adverse cardiovascular effects. The application of PEEP reduced (P less than 0.001) ET-CO2. There was no net increase in ET-CO2 after CO2-insufflation compared to the measurement after induction of anesthesia. This is in contrast to earlier studies without PEEP where a significant net increase in ET-CO2 was reported after CO2-insufflation.