The study was planned to evaluate efficacy and costs of endovascular sclerotherapy (ES) in comparison with surgery and surgery associated with sclerotherapy in a prospective (10-year follow-up), good-clinical-practice study. Patients with varicose veins and pure, superficial venous incompetence were included. Of the patients randomized into the three groups 39 (group A) were treated with ES, 40 (B) with surgery + sclerotherapy, and 42 with surgery only (C). Surgery consisted of ligation of the SFJ (saphenofemoral junction) and of incompetent veins detected with color duplex. Of the preselected 150 patients, 121 subjects entered the study; 96 completed the 10-year follow-up (mean age 52.6 +/- 6 years; 51 men, 45 women). Dropouts were due to nonmedical problems. At 10 years no incompetence was observed in subjects treated with SPJ ligation (B and C). In the ES group 18.8% of the SFJs were patent and incompetent and in 43.8% of limbs the distal (below-knee) venous system was still incompetent [16.1% in the surgery + sclerotherapy group (p < 0.05) and 36% in the group treated with surgery only (p < 0.05 vs B and 0.05 vs A)]. Color duplex of the long saphenous vein indicated atrophy or obstruction of a segment (average 6.7 cm) after SFJ ligation (4.2 cm after ES). The cost of ES was 68% of surgery while the cost of surgery and sclerotherapy was 122% of surgery only. Endovascular sclerotherapy is an effective, cheaper treatment option, but surgery after 10 years is superior.