Objective: It was reported that intensive immunosuppressive therapy is the current treatment of choice for patients with aplastic anemia who do not have histocompatible siblings or who are otherwise ineligible for alogenic bone marrow transplantation. We therefore designed a clinical study to establish the efficacy of intensive immunosuppressive therapy in these patients.Methods: Ten patients with severe aplastic anemia were treated with Antithymocyte globulin (ATG) 15 mg/kg/d for 10 days in 4 hours infusion, Cyclosporine A (CsA) 10 mg/kg/d p.o initially and regulated according to the serum CsA level for 3-6 months and méthylprednisolone 1 mg/kg/d as a short infusion for 2 weeks.Results: The hematologic response was achieved in 7 of the 10 patients, in a mean duration of 102.3 (30- 168) days. All of the responders are in continuing remission for a median of 25.2 (7-60) months. Three of the non-responders died of intercurrent infection.Conclusion: In this study we achieved a high hematologic response with intensive immunosuppressive therapy as reported in the literature.