Twenty children with hematologic malignancies were treated with bone marrow transplantation using histoincompatible donor marrow depleted of T lymphocytes. CT-2 and complement were used to deplete the T lymphocytes. Engraftment was not a major problem in those receiving increased pre- and posttransplant immunosuppression. Five of the 20 children are currently alive and disease-free. Complications in the other children included engraftment problems, cyclosporin toxicity, infections, and bleeding. However, for most children, durable engraftment was seen. Thus, the nonavailability of histocompatible donors is no longer a contraindication to allogeneic bone marrow transplantation for those at high risk of relapse.