The purpose of this study is to describe the infiltration of mast cells as well as T and B cells in the walls of thrombotic varicose great saphenous veins. Sections were obtained from venous segments of patients with varicose veins and stained with toluidine blue for mast cells, while immunohistochemistry for T cells (using CD45RO antibody) and B cells (CD20) was analyzed using light microscopy after staining. The number of mast cells, T, and B cells observed in thrombotic varicose veins was 1.925 ± 1.203, 72.038 ± 34.707, and 19.519 ± 9.899, respectively. In varicose veins, the corresponding values were 0.265 ± 0.099, 0.600 ± 0.432, and 0.488 ± 0.400. Significantly higher number of mast cells, T cells, and B cells were observed in thrombotic varicose veins compared with control veins. A significant difference was not observed between the varicose group and control group. Thrombi in varicose veins can induce infiltration of mast cells, T cells, and B cells, which may be involved in the remodeling of venous walls.