BACKGROUND To compare the efficacy of ligation after foam sclerotherapy (FSL) with foam sclerotherapy (FS) alone for patients with varicose veins prospectively. METHODS Ninety-four patients with varicose veins underwent foam sclerothrapy alone and 88 patients with varicose veins received FSL. Patients were followed up at 1, 3, 6, and 12 months after treatment. The postoperative complications were documented prospectively. RESULTS In comparison with patients who underwent FSL, patients treated with FS only had higher incidence of phlebitis within 4 weeks (14.9% vs. 1.1%, P = 0.002) and at 6 months (10.6% vs. 0, P = 0.002) after treatment and had higher incidence of tenderness or discomfort (9.8% vs. 0, P = 0.003) and recanalization rate (8.5% vs. 1.1%, P = 0.007) at 6 months after treatment. All patients in both groups had no deep vein thrombosis and pulmonary embolism. CONCLUSIONS Patients treated with FSL have less postoperative complications than those with foam sclerotheray alone. FSL is an alternative procedure for management of patients with varicose veins. Also, a randomized prospective study is required to observe the long-term outcomes of the FSL.