Aim. To compare two different tactical approaches to the prevention of venous thromboembolic complications (VTEC) after phlebectomy in the patients presenting with primary varicose veins. Material and methods. The present prospective non-randomized comparative study included 116 patients with primary varicosis. Fifteen (13%) of them (presented with class C2 varicose veins, 76 (66%) with C3, 29 (17%) with C4, 4 (3%) with C5, and 1 (1%) with class C6 lesions. All the patients were hospitalized and underwent phlebectomy in the great and small saphenous vein basins. The patients of the study group (n=69) were considered to have at least the moderate risk of development of VTEC; they were treated with low-molecular weight heparins during not less than 7 days. In the patients of the control group (n=47), the risk of VTEC, the necessity and method of prophylaxis in accordance with the standard tactics were assessed by the attending doctors. The control ultrasound angioscanning (USAS) for the detection of postoperative thrombosis of deep veins was carried out within 3-7 days after phlebectomy; simultaneously, clinical symptoms characteristic of pulmonary embolism were evaluated. The main endpoint for the assessment of treatment effects was the frequency of all postoperative VTEC. Results. The two groups were matched for age, gender, duration and clinical class of the disease. The difference were found only in respect with duration of phlebectomy; namely, in the study group it was longer than one hour more frequently than in control patients. Deep venous thrombosis was diagnosed in 4 (6%) of the patients in the study group and in 9 (19%) control patients (p=0.035). No other variants of VTEC were documented in the patients of either group. Conclusion. The interpretation of each and every case of combined phlebectomy in the patients with primary varicose veins as the conditions with moderate or high risk of VTEC as well as the use of pharmacoprophylaxis with low-molecular weight heparins for at least 7 days makes it possible to significantly reduce the frequency of postoperative deep venous thrombosis.