A 34 year old woman with sickle cell (SS) anemia and chronic renal failure of unknown etiology was maintained on dialysis for 11 months before she received a cadaveric renal transplant. After 24 months, transplant function is excellent although a mild urinary concentrating defect (Umax = 532 mOsm/liter) is present. Renal biopsies five and 11 months after transplant revealed mild focal interstitial infiltrates and mesangial thickening. A major complication has been the reemergence of numerous severe painful crises, inferred to be caused by an increased blood viscosity consequent to a rising hematocrit value, after a hiatus of many years. The succession of crises was stopped with a prophylactic partial exchange transfusion program, reemerged when the program was discontinued, and was stopped again when the transfusion program was reinstituted. We conclude that renal transplantation may be successfully performed in patients with sickle cell disease. Complications of the hemoglobinopathy may develop, but painful crises can be successfully managed with judicious transfusion therapy.