The association of an early steroid-resistant rejection (SRR) with HLA-DR antigens was analyzed in 410 kidney transplantations. A severe SRR leading to a poor (45%) 1-year graft survival (GS) occurred in 22 transplantations (5%). An acute reversible rejection (ARR) with a GS of 94% was found in 80 transplantations (20%). For the 308 (75%) transplantations with no early rejection episodes the GS was 91%. HLA-DR5 and -DR8 present in the donor as incompatible antigens were strongly associated with SRR. Further, a mismatched DR1 from the kidney donor predicted a rejection, either reversible or irreversible. These findings may have practical implications for an early diagnosis of SRR and for considering of rescue therapy whenever transplantation with disparities in these loci has been performed.