Withdrawal of azathioprine in renal transplant recipients with chronic active hepatitis and persisting HBs antigenemia was recommended for its beneficial effect on the course of liver disease. We report here three cases in which azathioprine treatment was stopped for this reason. One of these patients lost his graft due to irreversible vascular rejection 6 years after successful transplantation. Decrease of graft function paralleled azathioprine withdrawal in a second patient. Data from other reports indicate that cessation of azathioprine treatment may be followed by decreased graft function or even graft loss. We conclude that the risk of altered graft function is substantial and this is too high a price to pay for a procedure that may not prevent chronic active hepatitis from progressing to cirrhosis.