Iliac vein compression syndrome (IVCS), the symptomatic compression of the left common iliac vein between the right common iliac artery and the vertebrae, is not an uncommon condition. The aim of this research was to retrospectively evaluate long-term outcome and the significance of endovascular treatment in patients with left IVCS. Between January 1997 and September 2008, 296 patients received interventional therapy in the left common iliac vein. In the second stage, 170 cases underwent saphenous vein high ligation and stripping. Two hundred and thirty-one cases were followed up over a period of 6 to 120 months (average 46 months) and evaluated for symptom improvement with color ultrasound and ascending venography. The stenotic or occlusive segments of the left iliac vein were successfully dilated in 285 cases, of whom 272 received stent implantation therapy. Most of the patients achieved satisfactory results on discharge. During the follow-up period, varicose veins were alleviated in 98.7% of the patients, and leg swelling disappeared or was obviously relieved in 84% of cases. About 85% of leg ulcers completely healed. The total patency rate was 91.7% as evaluated with color ultrasound and 91.5% with ascending venography. Endovascular treatment of IVCS provides effective symptomatic improvement and good long-term patency in most patients.