Three hundred forty-seven recipients of primary cadaver kidney transplants were analyzed in relation to ATG therapy, pretransplant transfusion, HLA-A, -B and -DR antigen matches, and level of PRA to the panel. Prophylactic ATG treatment increased transplant survival significantly when compared with the non-ATG group. The beneficial effect of pretransplant blood transfusions was not apparent when the recipients received prophylactic ATG treatment. No correlation was noted between HLA-A and -B antigen matches and transplant survival. There was no significant difference in the transplant survival between patients with zero DR antigen match kidneys and those with one DR antigen-match kidney. The number of transplants with two DR antigen-match kidneys was too small to be conclusive. The recipients in whom PRA did not develop despite pretransplant blood transfusions seemed to have better transplant survival than those in whom PRA did develop in response to blood transfusions.