In 121 primary cadaver kidney grafts, a significant increase in graft survival has been observed in recipients transfused prior to transplantation, whatever the number of units received or the time of administration. This beneficial effect of blood transfusion was shown to be independent of the recipient's sex, blood group, HLA-A, B match grade and dialysis time. In longitudinal screenings, the incidence of post-transplant antibodies did not differ according to transfusion status of recipient. However, the graft survival was significantly improved in transfused patients without antibody or with an IgM anti-B (cold) antibody (95% survival at 4 years) as compared to nontransfused with the same characteristics. Patients with IgG anti-B (warm), anti-T or anti-PBL antibodies IgG/IgM shared a uniformly poor graft prognosis whether or not they had been transfused.