Acute renal failure developed in a patient who received 56 grams of vancomycin intravenously over a 10 day period. The resulting serum vancomycin level was 284 micrograms per ml and declined to 140 micrograms per ml in a linear fashion with the institution of continuous arteriovenous hemofiltration (CAVH). Our conclusion is that high blood vancomycin levels may be nephrotoxic and CAVH may be an effective means of vancomycin removal in patients with acute renal failure.