Objective To introduce the technique of DSA-guided foam sclerotherapy and evaluate its feasibility,safety and curative effects for treatment of lower extremity varicose ulcer (LEVU). Methods A total of 48 legs in 36 selected LEVU patients received DSA-guided foam sclerotherapy with lauromacrogol, with the area of varicose ulcer being 1-7 cm². After high ligation of the great saphenous vein, DSA-guided foam sclerotherapy was performed using 4F catheter to inject the foam of lauromacrogol into the lower extremity varicose to selectively block the great saphenous vein and communicating vein. Ulcer with area larger than 5 cm2 was treated with debridement and skingrafting, and that smaller than 5 cm2 was covered with sterilizing vaseline gauze. All cases wore Ⅰ class compression elastic stockings in the first week after operation and wore Ⅱ class compression elastic stockings from the second week for 3 to 6 months. All patients were given postoperative prophylactic antibiotics and local dressings were changed regularly. Results The procedure was technically successful for all the 48 legs. The injected sclerosant volume ranged from 3.5-8.5 mL for each patient,with an average dose being 6.5 mL; there were no serious complications. The patients could get down the bed and move about on the day after treatment. Two weeks later the ulcer was cured in 38 (79.2%) limbs, reduced in size in 8 (16.7%) limbs, and remained unchanged in 2 (4.2%) limbs. The varicose ulcer disappeared in 45 (93.8%) limbs during 6-12 months follow-up, and 3 (6.2%) limbs had recurrent ulcer. Conclusion DSA-guided foam sclerotherapy of lauromacrogol is a safe, mini-invasive and effective treatment for LEVU, which makes it possible for quick healing of the ulcer after operation.