Abstract: To clarify effects of renal failure on salivary distribution of Levofloxacin (LOFLX), a quinolone antibiotics, blood and saliva were collected from the double-step 5/6th-nephrectomized and sham-operated (control) rats after bolus i.v., administration of Levofloxacin (10 mg kg-1). The concentrations of Levofloxacin in these samples were determined by high-performance liquid chromatography. Renal failure induced by the partial nephrectomy significantly elevated plasma levels and cumulative salivary excretion of Levofloxacin when compared to control rats. Total body clearance was significantly decreased by the renal failure, although salivary clearance of the partially nephrectomized rats was larger than that of the control. The saliva/plasma concentration ratios in the rats with renal failure were significantly greater than those in the control rats. The results of this study suggest that the salivary excretion of Levofloxacin is significantly increased by renal failure.