Sevoj1.urane degradation by carbon dioxide absorbents during low - Jlow anesthesiaforms compound A. which causes nephrotoxicity in rats. This study was done to evaluate post operative renal and hepatic functions after patients were administered Sevoj1.urane under conditions designed to generate high concentration of compound A. Consenting forty patients ASA physical status I, II with normal pre operative renal and hepatic function undergoing anesthesia for elective surgery with planned duration exceeding 2 h. They were randomized to receive Sevoj1.arane (n=20) or Isoj1.arane (n=20) in oxygen. Total gas flow was iLlmin. opioid doses were minimized and barium hydroxide lime was used to maximize anesthetic degradation. Blood and urine were obtained before and 1.2 and 3 days after anesthesia for laboratory evaluation. Sevoflurane and Isoj1.urane groups were similar with respect to age, weights sex. ASA status and anesthetic duration (2-4h). There was no significant difference between anesthetic groups in postoperative serum creatinine. BUN, and urinary excretion of protein .Post operative alanine and aspartate amino transferase concentration .were not different between the anesthetic groups. It is concluded that renal tubular and hepatic effects of 10w-j1ow Sevoj1.urane and Isoj1.urane were similar as assessed using both conventional measures of renal and hepaticfunctions .Moderate duration of lowj1. ow Sevoj1.urane anesthesia, during which compound A formation occurs appears to be as sqfe as low-j1.ow Isoj1.urane anesthesia