There are numerous reports in the literature concerning the use of laparoscopy for evaluation of abdominal trauma victims. The safety of laparoscopic evaluation in trauma patients with potentially severe intracranial injuries has not yet been analyzed. This study investigates the effect of pneumoperitoneum on intracranial pressure (ICP) and cerebral perfusion pressure. Five 30-kg pigs were monitored for ICP, mean arterial pressure (MAP), arterial blood gases (ABGs), and intra-abdominal pressure (IAP) for 30 minutes before, during, and after pneumoperitoneum. These series of measurements were repeated after artificially elevating the ICP with an epidural balloon. The mean ICP at baseline was 13.46 +/- 1.01 mm Hg. The mean ICP during pneumoperitoneum was 18.72 +/- 1.50 mm Hg (p = 0.0001). The ICP increased to 27.40 +/- 0.93 mm Hg (p = 0.0001) after the ICP was raised artificially to a new baseline of 22 +/- 1.75 mm Hg with the epidural balloon. These increases were independent of changes in arterial PCO2 or arterial pH. Pneumoperitoneum during laparoscopy may increase ICP and must be used cautiously in evaluating patients with severe head injuries.