BACKGROUND The aim of this study was to explore the effects of recombinant human granulocyte macrophage colony stimulating factor (rhGM-CSF) on deep second-degree burn wound healing. METHODS In this study, 95 patients with a total of 190 burn wounds were treated with either rhGM-CSF or placebo, separated into 2 groups by treatment type. Wound healing rate, wound healing time, histopathological condition, and scar scale were all compared between the 2 groups. RESULTS The healing rates in the rhGM-CSF group were remarkably higher than those in the placebo group (P < .01). The wound healing time in the rhGM-CSF group (18.8 ± 7.6 days) was significantly shorter than that in the placebo group (25.5 ± 4.6 days, P < .01). On the 14th day and 28th day, the average optical density of vascular endothelial factor (VEGF) in the rhGM-CSF group was larger than that in the placebo group. Meanwhile, the average optical density of fibroblast growth factor (FGF) in the rhGM-CSF group was also larger than that in the placebo group. Furthermore, the Vancouver scar scale scores of pigmentation, pliability, height, and vascularity were notable lower in the rhGM-CSF group than those in the placebo group (P < .01). CONCLUSION The results suggest that rhGM-CSF can significantly accelerate deep second-degree burn wound healing.