Regulatory T (Treg) cells are a group of negative regulatory cells, which have a potent ability to suppress the functions of other immune cells. Treg cells have four subsets: CD4+ Treg, CD8+ Treg, natural killer T cells (NKT) and double negative Treg (DN Treg) cells. Tumor specific Treg cells may limit the efficacy of anti-tumor response to gynecologic cancers. It has been identified recently that tumor cells could induce the production of tumor specific Treg cells. The accumulation and expansion of tumor specific Treg cells in tumor and the conversion of conventional CD4+ CD25 + T cells to Treg cells may contribute to the increased number of Treg cells in tumor microenvironment. Treg cells play an important role in the mechanism of immune inhibition and immune escape of gynecologic cancers. This paper briefly reviews advances in recent research on association of regulatory T cells with immune function in gynecologic cancers. Copyright© 2011 by the Editorial Board of Tumor.