Intraoperative serial changes in systemic hemodynamic parameters and in the results of renal function tests were studied in 7 patients who underwent laparoscopic cholecystectomy (LAP) in which intra-abdominal pressure was maintained at 12 mm Hg, and in 7 patients who underwent minilaparotomy cholecystectomy (MINI). No significant changes were observed in the parameters in the MINI group during the operation. However, urine output, effective renal plasma flow and glomerular filtration rate in the LAP group were decreased 60 min after initiation of pneumoperitoneum.