Between January 1,1968 and March 1977, 100 of 131 patients who lost their first transplant at the University of Minnesota received a second renal allograft. Overall patient survival in the retransplanted group was 10% less than that in the dialysis group. The best results (graft function and patient survival) were seen in young patients, nondiabetics, patients who received two sequential living related groups, and in those whose first graft was lost secondary to chronic rejection. The poorest results were seen in older patients (>40 years), diabetics, and patients with acute rejection during the initial graft. Shared donor antigens do not affect graft outcome. These findings, although not the product of a randomized prospective study, may be useful in advising patients of the relative risks of retransplantation or hemodialysis.