18 patients with severe aplastic anemia (SAA) but without an HLA-identical sibling were treated by antilymphocyte globulin (ALG) followed by infusion of marrow cells from a semi-compatible family donor. 13 of these received low dose androgens after ALG: 11 (85%) achieved stable remission without transfusion requirement. One patient relapsed after 4 months, one patient with only partial remission died from infection. None of the 4 patients who did not receive androgens after ALG achieved remission. ALG, marrow and low-dose androgens represent a promising therapy for SAA and can be favorably compared with allogeneic bone marrow transplantation.