From January 1, 1968 to December 31, 1973, 50 patients received two or more kidney transplants. Patient and graft survival was highly dependent upon the source of the donor and to a lesser extent the functional duration of the first transplant and the elapsed time between first and second graft. Survival (patient and graft) was best in patients receiving two related grafts and worst in patients receiving two sequential cadaver grafts. Intermediate rates of success followed cadaver transplantation after rejection of a related graft. The highest failure rate was encountered when those patients who sustained an early loss of the first cadaver graft received a subsequent cadaver graft within a few months. We recommend removal of the acutely rejected graft and delay prior to retransplantation of patients who rapidly reject cadaver grafts in the face of maximal doses of immunosuppression. A delay will permit recovery from both the immunosuppression and any underlying subclinical infections, and will permit the recognition of anti-HL-A antibodies which may not be manifest soon after rejection. Retransplantation of the patient who is slowly rejecting the first kidney does not require prior removal of the rejected graft or delay in transplantation.