In a case of liver transplantation, sevoflurane metabolism was studied to investigate if sevoflurane has an extrahepatic metabolism or possible nephrotoxicity in the presence of chronic liver disease. Plasma blood urea nitrogen (BUN) and creatinine and urine levels of N-acetyl glycosaminidase (NAG) and beta 2 microglobulin were assessed intraoperatively and for 11 days postoperatively. We observed a close relation between urine NAG excretion and urine inorganic fluoride levels in the intraoperative period and early postoperative days. The NAG levels were greater than normal despite the peak serum inorganic fluoride concentration of 18.94 mu mol/L. No impairment was observed in serum BUN or creatinine levels in these periods.