Although sevoflurane is used in clinical anesthesia, its effects on renal function and inorganic fluoride (F-) kinetics in patients with chronic renal failure (CRF) have not been determined. We investigated F- kinetics and renal tubular function in sevoflurane anesthesia in CRF patients having hemodialysis. Five patients dialyzed and five with normal renal function undergoing parathyroidectomy or thyroidectomy were anesthetized with sevoflurane (1.0%-2.5%) and nitrous oxide in oxygen. Serum and urine levels of F-, blood urea nitrogen (BUN), serum creatinine (Cr), serum and urine beta 2-microglobulin (BMG) levels, and urine N-acetyl-beta-D-glucosaminidase (NAG) level were measured. BUN, Cr, and serum and urine BMG levels were significantly higher in the CRF patients than in the controls. There were no differences in serum F- level, rate of elimination, and area under the curve of serum F- levels between the two groups. However, the CRF patients had a significantly lower level of urine F- than control subjects. These data suggest that the F- kinetics in the CRF patients is different from that in normal renal function subjects. This clinical study with a limited number of patients may facilitate further studies to define the mechanisms of differences in the F- kinetics between normal subjects and CRF patients having hemodialysis after sevoflurane anesthesia.