The waiting list for cadaver kidney transplantation continues to grow. Yet there has been little increase in the number of living-donor transplants. At many centers, willing relatives are turned down as potential donors because of poor HLA ABDR matching with the recipient. It has been our policy to accept the 0-haplotype-match (0-HTM) living-related donor. We studied long-term (6-year) outcome of 0-HTM transplants compared with the outcome of transplants from 1- and 2-HTM recipients and from cadaver donors. Since 1984, 352 adults have received primary living-related renal transplants, and had a minimum of 1 year of follow-up: 92 2-HTM, 216 1-HTM, and 44 0-HTM. In the same period and with the same follow-up, 362 adults have received primary cadaver (CAD) renal transplants. Immunosuppression consisted of cyclosporine, azathioprine, and prednisone (triple therapy) for living-donor and sequential therapy for CAD recipients. ABDR match (mean +/- SD) for 0 HTM was 1.3 +/- 8; CAD, 2.0 +/- 1.6; % peak panel-reactive antibodies (PRA) for 0 HTM was 1.2 +/- 5.3; 1 HTM, 6.7 +/- 20; 2 HTM, 7.5 +/- 21; CAD, 15.5 +/- 30. The percentage of PRA at the time of transplant for 0 HTM was .7 +/- 4.4; 1 HTM, 4.1 +/- 1.6; 2 HTM, 6 +/- 18; CAD, 7.2 +/- 20. While the number of ABDR matches was significantly fewer for 0 HTM than for the other groups, the % PRA at transplant and the peak % PRA were less in the 0-HTM group. Other demographics were not significantly different. Patient survival was significantly lower in the CAD group vs. 2-HTM recipients (P < .05). The living-related grafts had significantly greater survival than the CAD grafts (P < .05), but there was no significant difference between 0-, 1-, and 2-HTM graft survival. The most common causes of graft loss in all groups were death and chronic rejection. In our experience, the long-term graft survivals of 0-HTM and 1-HTM transplants are the same, and both are superior to CAD results, using 0-HTM living-related donor transplants should be continued and encouraged.