BACKGROUND The increasing success of renal transplantation is paralleled by the increased size of the waiting list. Efforts to increase the donor pool have included the use of living-unrelated kidney donors (LURDs). METHODS During a 12-year period our center performed 309 transplantation from living donors; 279 patients received living-related donor (LRD) transplants, and 30 patients received LURD transplants. During the same period 543 patients received cadaveric renal donor transplants. A total of 86.7% of LURD transplants were spousal transplants. A total of 29% of the patients who received LRDs were human leukocyte antigen-identical with their donors and 53% were haploidentical, versus 0 human leukocyte antigen-identical or haploidentical in the LURD group. RESULTS Twenty-seven (90%) Of 30 LURD recipients are alive, as are 240 (86%) of 279 LRD recipients. Mean current creatinine is 1.6 mg/dl for the LURD group and 1.7 mg/dl for the LRD group Kaplan-Meier 1- and 5-year graft survival was 94.9% and 82.9% for the LRD group, 93.1% and 85.9% for the LURD group (p = not significant), and 84.6% and 70.7% for the cadaveric renal donor group (p < 0.05). CONCLUSIONS LURD patient and graft survival is comparable to LRD transplants despite inferior human leukocyte antigen matching. LURD transplant survival is superior to that of cadaveric renal donor transplants. LURDs are an excellent but underused source of organs for renal transplant recipients.