Chronic granulocytic leukemia (CGL) developed in a 31-year-old man after he underwent a third renal transplant. The leukemia was initially controlled with azathioprine sodium and prednisone therapy, but eventually it entered blast cell crisis. This was controlled with an adult acute lymphocytic leukemia protocol with an excellent response. Despite discontinuing treatment with azathioprine and with the use of busulfan to control the peripheral WBC count, the patient maintained stable renal function for one year following treatment of the blast cell crisis and subsequently died of sepsis. We suggest that CGL after renal transplantation is similar to that observed in the general population and can be treated with the usual chemotherapeutic agents for the disorder without sacrificing renal function.