212 cyclosporine-treated recipients of mismatched first cadaveric renal allografts are evaluated with respect to the effect of pretransplant random blood transfusions. It is determined that transfusions do not effect patient survival or morbidity. Pretransplant random blood transfusions correlate with significantly improved allograft success. There is also a trend, although not statistically significant, for further improvement of allograft survival with increasing numbers of transfusions. The transfusion effect is not related to the time at which the transfusions are given up to 2 years prior to transplantation. Transfused patients have a higher percent reactive antibody (PRA) than untransfused patients, but this does not cause them to wait for a cadaveric allograft significantly longer than the untransfused patients. Rejections are less severe in transfused patients. It is concluded that cyclosporine-treated recipients of first cadaveric renal allografts benefit from pretransplant blood transfusions.