Sickle cell disease (SCD) is associated with significant morbidity, a decreased lifespan and a poor quality of life. While there is increasing evidence that hydroxyurea can improve the course of severe SCD, hematopoeitic stem-cell transplantation (HSCT) remains the only curative option for SCD. Multicenter trials have shown that HSCT after myeloablative conditioning has excellent outcomes in children with SCD, with an overall survival ranging from 93 to 97% and an event-free survival between 82 and 86%. With better understanding of the course of SCD in adulthood, there has been increasing interest in making HSCT a viable intervention in adults. Nonetheless, older patients with severe disease have not been considered suitable candidates because of the higher risks associated with myeloablative conditioning. Recently, reduced-intensity regimens have been used in adults with good results, albeit in a small number of patients. The main limitation of HSCT in both adults and children with SCD remains the lack of availability of fully matched HLA sibling donors for patients meeting transplant criteria.