Objective To asses the clinical effectiveness and safety of combined treatment with antilymphocyte globulin (ATG) and cyclosporine A (CSA) versus antilymphocyte globulin alone in patients with aplastic anemia (AA). Methods Randomized controlled trials (RCTs) were identified from MEDLINE (1966 to September 2007), EMBASE (1984 to September 2007), The Cochrane Library (issue 4, 2007) and CBM-disc (1978 to September 2007). The references of eligible studies were hand searched. RCTs involving ATG and CSA in the treatment of AA were included. Data were evaluated and extracted by two reviewers independently with designed extraction form. The Cochrane Collaboration’ s RevMan 4.2.10 software was used for data analyses. Results Two RCTs involving 160 patients were included. Two studies showed that the effective rate in the ATG+CSA group was significantly higher than that in the ATG group (Plt;0.0001). Two studies indicated that the survival rate in the ATG+CSA group was improved compared with the ATG group (P=0.0002). One study reported adverse effect. The ATG group caused more fever and serum diseases compared with the ATG+CSA group, but the ATG+CSA group had a higher incidence of hepatotoxicity. Conclusion Treatment with ATG+CSA for aplastic anemia has higher effective rate and survival rate than ATG alone. More trials of high quality are required.