We present the first case of retrograde ablation of the small saphenous vein to treat active venous ulceration. A 73-year-old gentleman with complicated varicose veins of the left leg and a non-healing venous ulcer despite previous successful endovenous treatment to his left great saphenous vein underwent mechanochemical ablation of his small saphenous vein with the ClariVein® system, under local anaesthetic, using a retrograde cannulation technique. Post-operatively the patient had improved symptomatically and the ulcer size had reduced. This report highlights that patients with small saphenous vein incompetence and active ulceration can be treated successfully with retrograde mechanochemical ablation.