The role of allogeneic hematopoietic cell transplantation (alloHCT) in human immunodeficiency virus (HIV)-positive patients is not known. Using the Center for International Blood and Marrow Transplant Research database, we retrospectively evaluated 23 HIV-positive patients undergoing matched sibling donor (n = 19) or unrelated donor (n = 4) alloHCT between 1987 and 2003. The median age at alloHCT was 32 years. Indications for alloHCT were diverse and included malignant (n = 21) and nonmalignant (n = 2) hematologic disorders. Nine patients (39%) underwent transplantation after 1996, the approximate year that highly active antiretroviral therapy became standard treatment. The median time to neutrophil engraftment was 16 days (range, 7 to 30 days), and the cumulative incidences of grade II-IV acute graft-versus-host disease (aGVHD) at 100 days, chronic GVHD (cGVHD), and survival at 2 years were 30% (95% confidence interval [CI] = 14% to 50%), 28% (95% CI = 12% to 48%), and 30% (95% CI = 14% to 50%), respectively. At a median follow-up of 59 months, 6 patients were alive. Survival appears to be better in the patients undergoing alloHCT after 1996; 4 of these 9 patients survived, compared with only 2 of 14 those undergoing transplantation before 1996. These data suggest that alloHCT is feasible for selected HIV-positive patients with malignant and nonmalignant disorders. Prospective studies are needed to evaluate the safety and efficacy of this modality in specific diseases in these patients.