In a homogeneous group of 299 first cadaver kidney allograft recipients transplanted within one single center between 1973 and 1983, we analyzed the influence of several factors on graft survival. All recipients received at least one blood transfusion before transplantation. Criteria of donor-recipient selection as well as immunosuppressive treatment policy have never changed significantly within the studied period. In contrast to matching for HLA-A and B antigens, DR-matching has a significant influence on early graft survival. Kidneys with zero DR-mismatches have a one year graft survival of 96.2% versus 75.6% for kidneys with 2 DR-mismatches (P less than 0.05). The presence or absence of DRW6 in the recipient as well as in the donor has no effect on graft survival. A preservation time less than 12 hours is accompanied by a decreased early graft survival. The long-term survival of kidneys from donors older than 30 years is significantly reduced. At 5 years graft survival of kidneys from donors younger than 30 years is 75% versus 53% for kidneys from donors older than 30 years.