Second renal allograft survival rates are lower than those of primary allografts. For recipients immunosup- pressed with azathioprine, prednisone, and Minnesota ALG (conventional immunosuppression), risk factors associated with decreased second graft survival have been identified: Age >40, cadaver donor, <6 months between primary graft loss and retransplantation, duration of primary graft function (6 months or 1 year, depending on the study), high peak panel-reactive antibody, number of human leukocyte antigen mismatches, and delayed graft function. In this study, we used a multivariate analysis to identify risk factors associated with decreased second graft survival in patients who did or did not receive cyclosporine. Results were compared with primary graft survival rates. Risk factors for patients receiving conventional im-munosuppression were: (a) primary graft loss caused by rejection ≥6 months (P=0.01 vs. either rejection <6 months or nonimmunologic loss); (b) cadaver donor (i°=0.005 vs. living related); and (c) interval between primary graft loss and retransplantation of ≥6 months (P=0.05 vs. <6 months). For CsA, risk factors that most decreased second graft survival were: (a) primary graft loss caused by rejection <6 months (P=0.11 vs. nonimmunologic loss); (b) conventional immunosuppression for the primary graft (P=0.08 vs. CsA immunosuppression); and (c) a peak PRA of ≥21 (P=0.14 vs. peak PRA of 1-20). For second graft recipients immunosuppressed with CsA, primary graft loss to either rejection >6 months posttransplant or nonimmunologic causes was not a risk factor for second graft survival. These data extend the recent reports of other investigators by identifying risk factors for retransplant recipients treated with CsA and by demonstrating that subgroups of patients in the retransplant population can be retransplanted without additional risk (i.e., their second graft survival rates are similar to primary graft survival rates). This may become more important if, in the future, organ distribution is based on graft survival data. If so, our data would support retransplantation in patients who are immuno-suppressed with CsA, especially those who lost their primary graft to either rejection ≥6 months posttrans- plant or nonimmunologic causes; who receive living related grafts; and who have a peak PRA of 1-20.