Aplastic anemia (AA) is a rare, life threatening disease. Allogeneic bone marrow transplantation (BMT) offers the only possibility of cure, i. e. life-long remission. The probability of survival after BMT from an HLA-identical sibling has clearly improved over the last years and at present is about 80% in patients < 16 years. Transplantation from alternative donors, however, faces unsolved immunological problems. For demographic reasons most patients lack a matched sibling donor. For these patients immunosuppressive therapy (IST) is the only alternative therapeutic approach. However this treatment has frequently resulted in clonal, i. e. potentially malignant disease. Overall probability of survival here is only 50%, in severely granulocytopenic patients (< 0.2 G/l) even lower. These individuals represent an important subgroup in pediatric AA. Some patients show only partial reconstitution of their hematopoiesis but satisfactory quality of life. Based on the results of prospective studies a protocol for IST in AA using anti-lymphocyte globulin (ALG), cyclosporin A (CSA) and G-CSF is presented. For BMT-patients likewise a protocol for conditioning (ALG, cyclophosphamide) and GvHD-prophylaxis is suggested. Standardisation and improvement of supportive therapy is the third important objective of this pilot protocol.