For the first time, we conducted a 2-center retrospective study to show the efficacy of antithymocyte globulin (ATG)-Fresenius S plus cyclosporine treatment of children with severe aplastic anemia. From March 1997 to May 2011, a total of 124 patients (median age, 7.5 y; range, 1.5 to 16 y) from 2 centers with acquired AA treated with an immunosuppressive therapy (IST) regimen, consisting of ATG-Fresenius S (5 mg/kg per day for 5 d) and cyclosporine, were enrolled. The response rate was 55.6%. The median time between IST and response was 6 (0.5 to 18) months. After a median follow-up time of 29 (6 to 153) months, the rates of relapse and clonal evolution were 3.2% and 0.8%, respectively. Overall, 17 patients (13.7%) died in this study: 14 resulted from sepsis, 1 resulted from intracranial hemorrhage, 1 occurred after hematopoietic stem cell transplantation, and 1 resulted from clonal disease progression. The 5-year overall survival rate for the entire cohort was 74.7%. IST responders had a better survival rate (100%) than nonresponders (70.7%). The use of ATG-Fresenius S plus cyclosporine as a first-line immunosuppressive treatment appeared to be effective for children with severe aplastic anemia in our study. ATG-Fresenius S could be another option in the treatment arsenal, especially in countries where the other ATG products are harder to acquire.