The majority of patients in need of allogeneic hematopoietic cell-transplants do not have HLA-matched donors available. Researchers recently performed a retrospective study including 582 patients with acute myeloid or lymphoid leukemia or myelodysplastic syndrome in need of hematopoietic cell-transplants. HLA-matched unrelated donors were found for 344 patients; 98 patients received a transplant from an HLA-mismatched donor; and 140 patients received a cord-blood transplant. Compared to patients with residual disease who received cord-blood transplants, patients with residual disease who had a matched transplant (adjusted hazard ratio, 1.69; 95% CI, 0.94 to 3.02; P=0.08) or mismatched transplant (adjusted hazard ratio, 2.92; 95% CI, 1.52 to 5.63; P=0.001) had a higher risk of death. Among patients with residual disease, cord-blood transplant recipients also had lower rates of relapse than patients receiving either matched or mismatched transplants. Similar trends were observed for patients without minimal residual disease. In conclusion, cord-blood transplants are beneficial for patients in need of allogeneic hematopoietic cell transplants, especially when HLA-matched donors cannot be found.