The effects of artificial pneumoperitoneum on intracranial pressure have not been clearly defined. Initial animal studies indicate that elevated intra-abdominal pressure might have a deleterious effect on intracranial pressure. We report a case in which intracranial pressure was monitored intraoperatively during laparoscopic cholecystectomy. Intracranial pressure increased abruptly when the peritoneal cavity was insufflated, with the operating table in the Trendelenburg position, and decreased slightly with elevation of the head of the operating table. Initial opening intracranial pressure values were re-established on desufflation of the abdomen. Intracranial pressure monitoring should be considered when planning a laparoscopic procedure on patients with the potential for decreased intracranial compliance. (Arch Surg. 1995;130:1011-1013)