The aim of the study was to evaluate the efficacy of surgery in combination with sclerotherapy in the treatment of severe chronic venous insufficiency.Material and methods. During the period between 2007 and 2009, 38 patients with symptoms of advanced chronic venous insufficiency - C4, C5 and C6, according to the CEAP classification- were subject to surgery in combination with sclerotherapy. The study group comprised 24 (63%) female and 14 (37%) male patients, aged between 42 and 95 years. Twenty-three patients were diagnosed with saphenous vein insufficiency, 14 with small saphenous vein insufficiency, and one with femoro-popliteal venous insufficiency. Based on the VCSS scale, disease symptoms were evaluated before the operation and six months after the surgical intervention. In cases of saphenous or small saphenous vein insufficiency, the patients underwent crossectomy, followed by ligation of the saphenous-femoral and small saphenous-popliteal ostia. The distal segment of the vein was obliterated using a 3% polidocanol foam solution. Control ultrasonography was performed 1, 3, 6 and 12 months after the procedure. Patients with crural ulcerations that did not heal by three months postoperatively were subject to additional epidermal grafts.Results. Statistical analysis of the VSCC point scale before and after the operation demonstrated a significant reduction in the following parameters: pain, presence of varices, edema, ulcerations, and use of compression therapy. Analysis showed an effective elimination of the main venous trunks. Among patients with venous ulcerations, spontaneous healing was observed during the nine months after the procedure was observed in 17 (94%) patients. In one patient, the ulceration was reduced by 30-40%. Neurological, ophthalmological and thromboembolic complications of the deep venous system were not observed.Conclusions. 1. The combination of surgery and sclerotherapy in the treatment of advanced chronic venous insufficiency is a method worthy of recommendation. 2. The method is effective with a low risk of complications, thus significantly shortening hospitalization and absence from work. 3. An evaluation of the disease stage based on the VCSS scale, before and after the operation, demonstrated a significant improvement.