Based upon data reported to the UNOS Renal Transplant Registry between 1998-2001, the overall one- and projected 10-year graft survival rates for 31,720 cadaveric kidney transplants were 89% and 51%, and for 14,162 living donor transplants they were 95% and 68%, respectively. These results represent improvements of 15% and 13%, respectively, over the 10-year graft survival rates reported for transplants performed during 1987-1989. Repeat kidney transplants accounted for 14% of deceased donor kidney transplants during 1998-2001 and the 3-year graft survival rates were significantly lower for second (77%) and multiply regrafted (73%) than for recipients of a first transplant (79%; p < 0.001). About 1,200 newly defined expanded criteria donor (ECD) kidneys were transplanted each year between 1998-2001. ECD kidneys represented 15% of deceased donor kidneys and yielded a significantly poorer 3-year graft survival rate (68%) and half-life (7.1 years) than kidneys from normal donors over age 5 (81% and 11.9 years; p < 0.001). The graft failure rates (censoring death with a functioning graft) were similar among recipients aged 31-50 and those aged 51-70 comparing both ECD and normal kidneys. The effect of HLA matching on kidney graft survival remains essentially unchanged after 30 years even with remarkable improvements in immunosuppression. Considering transplants performed between 1995-2001, matching for antigens at the HLA-A,-B, and -DR loci resulted in a 16% higher projected 10-year graft survival rate when compared with grafts mismatched for 5-6 HLA antigens (p < 0.001). The 10-year graft survival difference associated with HLA matching in US transplants performed between 1979-1984 and reported to the UCLA Registry before the introduction of cyclosporine was also 16%. The 3-year graft survival rates for zero HLA-DR mismatched normal kidney grafts (excluding ECD kidneys) were 83%, the same as for recipients of 0 HLA-BDR mismatched grafts. Those with one or 2 DR antigens mismatched had significantly poorer outcomes (80% and 77%, p < 0.001). Living donor transplants from offspring to parents and from genetically unrelated donors including spouses increased more than 5-fold since 1994. In 2001 the number of non-spouse unrelated donors surpassed the number of spouses (701 and 616, respectively). Despite the growing number of these HLA-disparate living donor transplants, their 3-year graft survival rates and half-lives remain as high as those for related donors sharing one HLA haplotype with the recipient. Laparoscopic donor nephrectomy now accounts for more than half of living donor surgeries reported to UNOS. There was no difference in graft survival or in early graft function associated with the type of donor surgery for 19,223 living-donor transplants between 1998-2001. Kidney transplants from non-heartbeating donors are beginning to increase and despite a significantly higher incidence of delayed function, 3-year graft survival rate was 79% for transplants between 1998-2001, the same as for conventional brain-dead deceased donor transplants.