Objectives: This prospective, non-randomised study was aimed at the assessment of prevalence of thromboembolic events in vascular patients routinely receiving antithrombotic prophylaxis following surgical revascularisation of the lower extremities. Material and methods: This study included 105 patients operated on for aortoiliac occlusive disease. Postoperatively all patients received pharmacological antithrombotic prophylaxis with low-molecular-weight heparin. Sonographic examination of the veins of low extremities was routinely performed three times: one day before the surgery, on the discharge day and 30 days after hospital discharge. Results: Thromboembolic complications were found in 21 patients (19.05%), including 18 patients with deep venous thrombosis and 3 with pulmonary embolism. Thromboembolic events were more prevalent in older patients (68.22 vs. 62.65 years), those with necrotic lesions of the limbs, with lower preoperative concentration of hemoglobin (7.89 vs. 8.61 mmol/l), higher of fibrinogen (455 vs. 357 mg/dl) and of platelet count (334 vs. 250 × 10 9 /l). Other risk factor comprised the number of transfused packed red blood cell units (3.39 vs. 1.45 units) and plasma units (1.61 vs. 0.39 units), and the length of stay in the intensive care unit (4.78 vs. 2.24 days). Conclusions: Vascular patients develop thromboembolism very often, despite pharmacological prophylaxis. Thus, routine scanning for deep vein thrombosis before hospital discharge in order to exclude thrombosis should be considered in this group. Also, an extended post-discharge thromboprophylaxis in these patients should be considered.