A girl with sickle cell anemia was treated with cord blood transplantation combined with hematopoietic growth factor. Cord blood cells were collected from a sister with an identical human leukocyte antigen complex who was a carrier of the sickle cell trait (hemoglobin AS). The patient had complete engraftment and no graft-versus-host disease. The persistence of a high level of fetal hemoglobin 6 months after engraftment was noted.