A 22-y-old woman was hospitalized for muscle weakness of her lower extremities after she sniffed approximately 6 l of pure toluene during the month prior to admission. The examinations on serum and urine revealed mixed hyperchloremic and high anion gap metabolic acidosis accompanied by impaired urinary acidification. Histopathological changes of the kidney were patchy areas of tubular injury. Acidosis normalized on the fourth day of admission, but both proximal and distal tubular dysfunction persisted. These findings indicate that toluene is a tubular toxin and may contribute to the development of distal renal tubular acidosis.