Objective To explore the effects of recombinant human growth hormone(rh-GH) on immune function in children with tetralogy of Fallot (TOF) after radical operation. Methods Thirty children with TOF were divided into two groups: conventional (n=20) and rh-GH (n=10, 0.2U/kg rhGH, sc., three times per week for 4 weeks). The immunoglobulin, complement fraction, lymphocyte subsets, and interleukins were determined. Results After treatment, the abnormal elevation of IgG, IgM, C_3, C_4, CD8~+ and CD19~+ in rhGH group decreased significantly at 1 week to 3 weeks; moreover, the abnormal descend of IgA, CD3~+, CD4~+, CD4~+/CD8~+, CD3~+/HLA-DR~+, and CD3~+/CD~ (16+56) in rh-GH group increased significantly at 1 week to 2 weeks compared to those of conventional group; and all recovered to the levels of control at 4 weeks. The interleukin-6 and tumor necrosis factor-? levels in the plasma and supernatant of peripheral blood mononuclearcytes decreased gradually at 1 week to 2 weeks after treatment compared to those of conventional group, and also recovered to the levels of control at 4 weeks. Conclusion rh-GH therapy could significantly improve immune function of children with TOF after radical operation.