To describe the short-term efficacy of a strategy of imaging-guided endovascular intervention for the treatment of patients with established postthrombotic syndrome (PTS). The medical records of 183 patients with venous disease who were seen in a single interventional radiology clinic were retrospectively reviewed. Study inclusion criteria were (i) endovascular intervention performed to treat established PTS from January 1, 2000, to March 10, 2009; (ii) patient age greater than 18 years; and (iii) availability of follow-up records. A total of 44 patients (20 men, 24 women; mean age, 42.2 y ± 14.1) with PTS who had received 72 interventions (iliac vein stent placement [n = 52] and endovenous laser ablation [EVLA; n = 20]) were identified. A reviewer who did not participate in their care evaluated the follow-up records; recorded the presence or absence of pain, swelling, and active ulceration; and categorized the degree of symptom improvement. Of 45 treated limbs in 40 patients with available follow-up, complete, partial, or no improvement of overall symptoms was observed in 46.7%, 33.3%, and 20.0%, respectively. The proportions of limbs with pain (35.0% after treatment vs 82.5% before; McNemar test, P < .01) and swelling (50.0% after treatment vs 90.0% before; P < .01) were significantly reduced after treatment with iliac vein stent placement and/or EVLA. Six of seven ulcerated limbs showed significant healing. The use of an endovascular strategy to treat patients with established PTS was associated with complete or partial symptom relief in 80% of patients at short-term follow-up.