A posterior midline incision was used for subfascial ligation of incompetent medial and lateral perforating veins in 57 limbs. The indications for surgery were recurrent ulceration in 41 limbs and severe skin changes in 16 limbs. At follow-up two years or more after surgery 48 limbs remained free from ulceration. Wound infection (7%) and necrosis (12%) healed with conservative treatment. In our experience the posterior approach is a good alternative to other methods for ligation of incompetent perforating veins in patients with advanced skin changes, including active ulceration.