Valvular insufficiency and varicose transformation in the small saphenous vein (SSV) system occur in 20—25% of the patients presenting with the primary forms of chronic venous diseases. The presence of a cosmetic defect and manifestations of disturbed venous outflow are considered to be  indications for the surgical treatment, with the conventional open intervention or modern endovascular technologies being the methods of choice. Aim. To estimate the results of echo-controlled microfoam sclerotherapy (ECMFST) of the  trunk and varicose tributaries of the small saphenous vein in the lower extremities. Material and methods. The present study involved 117 patients (100 women) presenting with valvular insufficiency in the small saphenous vein (n=122). The age of the patients varied from 20 to 57 (mean 33.2±5.4) years. Their examination included detailed analysis of medical histories, clinical check-up, evaluation of the phlebological status, ultrosonographic study, classification by CEAP and VCSS, and filling the disease-specific CIVIQ-29 questionnaire. All the patients underwent ECMST. The outcome of the treatment was estimated in the course of planned control examinations that included an ultrasound study and photography of the affected extremities within 10 days, 3, 6, and 12 months after the ECMFST procedure. Results and Discussion. The duration of the follow-up period varied from 3 to 5 (mean 3.9±1.5) years. The regular clinical and ultrasound control over 79 patients (79 lower extremities) lasted 5 years. Complete obliteration of SSV and its varicose tributaries after a single procedure was achieved in 79 (64.7%) cases. The remaining patients required from 2 to 3 repeated procedures performed with an interval of 3—4 weeks to reach the same condition. The dynamic observation of the patients following ECMST of the small saphenous vein revealed the lowering of the clinical class of  the disease, the decrease of the venous clinical severity score (VCSS) from 4.3±0.7  to  1.2±0.3 (p<0.0001), and the significant improvement in the global quality of life. Forty six patients (48 lower extremities/39.4%) developed adverse side reactions and complications including 27 (22.1%) cases of varicothrombophlebitis and 13 (10.7%) cases of deep venous thrombosis. Rapid (within 12 months) recanalization of the SSV trunk and relapse of varicose syndrome required open phlebectomy to be performed in 2 patients (2 (7.4%) lower extremities). Nine other patients (9 (7.4%) lower extremities) underwent surgical intervention within 3—5 years to manage the relapse of the disease. Complete obliteration of the SSV trunk up to the saphenopopliteal junction persisted during at least 3 years in 81 (66.4%) lower extremities while partial restoration of the SSV lumen in the absence of pathological blood reflux and recurrent varicose syndrome occurred in 30 (24.6%) lower extremities. Ninety (83.8%) patients had no specific venous complaints whatever. Eight (6.8%) respondents had aesthetic complaints arising from the appearance of new varicose veins and telangiectasias. The average cost of one procedure of echo-controlled microfoam sclerotherapy of the small saphenous vein and its tributaries including depreciation expenses for the ultrasound equipment and the price of the RAL-standard compression hosiery was 3,200 roubles. Conclusion. Echo-controlled microfoam sclerotherapy provides an effective and safe tool for the office treatment of the patients presenting with vulvular insufficiency of the small saphenous vein and varicose dilatation of  its tributaries. In the majority of the cases, its application produces a good clinical and aesthetic result within 3 to 5 years.