Aim. To study the long-term course of post-thrombotic syndrome after distal deep vein thrombosis and popliteal vein thrombosis. Material and methods. We carried out a one-step (cross-sectional) retrospective study of the long-term results of the treatment of 89 patients presenting with post-thrombotic syndrome after distal deep vein thrombosis and popliteal vein thrombosis. They were divided into two groups. Group 1 was comprised of 59 patients after isolated distal thrombosis (36% of men and 64% of women) at the mean age of 56 years, with the average period from the onset of thrombosis 40.5 months). Group 1 consisted of 39 patients who had experienced thrombosis affecting the upper segment of the popliteal vein without its extension into the femoral vein (19 (48%) men and 20 (52%) women) at the mean age of 56 years, with the average period from the onset of thrombosis 40.5 months). Results. Class C3—C6 disease was diagnosed in 38% and 62% of the patients in groups 1 and 2 respectively. The venous clinical severity score (VCSS) averaged 3 in the patients of group 1 and 4.3 in those of group 2 (p=0.019). The frequency of ipsilateral deep vein thrombosis in these groups was 12 and 10% respectively. The assessment of severe post-thrombotic syndrome as a risk factor and incompliance with the prescribed anticoagulation and compression treatments has demonstrated the absence of any appreciable influence of these factors on the clinical outcome of the disease. The differences in the quality of life evaluated with the help of the SF-36 questionnaire were apparent only when the criteria for general health were employed. No differences were revealed using the CIVIQ2 questionnaire. Conclusion. The long-term prognosis in the patients who suffered only distal deep vein thrombosis is more favourable than in those with thrombosis extending into the popliteal vein. Nevertheless, such characteristics as the frequency of relapses and deterioration of the quality of life in the latter group are not significantly different from those in the patients with distal vein thrombosis despite the more pronounced clinical symptoms of post-thrombotic syndrome.