Objective To assess the effectiveness of intravenous immunoglobulin G (IVIG) in reducing the need for exchange transfusion in neonates with proven haemolytic disease due to Rh and/or ABO incompatibility. To evaluate the effectiveness of IVIG in reducing the duration of phototherapy and hospital stay. Methods We electronically searched CENTRAL, MEDLINE (1966 to May 2008), EMBASE (1992 to May 2008), CBMdisc (November 1979 to May 2008), and also checked the reference lists of all papers identified. According to the Cochrane Handbook for Systematic Reviews of interventions, randomized controlled trials comparing IVIG and phototherapy with phototherapy alone in neonates with Rh and/or ABO incompatibility were identified and analyzed. Results Six RCTs were included. The meta-analysis showed that, IVIG can significantly decrease the requirements of exchange transfusion (RR=0.27, 95%CI 0.18 to 0.42), the duration of hospitalization (WMD= –1.11, 95%CI –1.60 to –0.63) and the duration of phototherapy (WMD= –0.82, 95%CI –1.16 to –0.47). Conclusions Intravenous immunoglobulin (IVIG) is recommended for treating hemolytic disease of the newborn because it is effective in decreasing the requirements of exchange transfusion, the duration of hospitalization and phototherapy. Well designed studies with large sample in multi-center are required for further proving.