To cover soft tissue defect, various types of flaps have been used. Although lateral supramalleolar flap has been used as rotation flaps or reversed island flaps to cover defects around the foot and ankle, there has been no report about its application as a free flap. The lateral supramalleolar island flap has proves to be supplied constantly by the terminal branch of the peroneal arterys perforating branch. The free lateral supramalleolar flap has the same skin territory. Its vascular pedicle can be extended to the main peroneal artery and vena comitans, which can be obtained by dissecting the peroneal vessels between the distal tibia and fibula through the interosseous membrane. We have successfully transferred this free flap in eight patients from April 1994 to February 1995. All of the patients had full thickness skin defects which were caused by contact thermal burn, electrical burn, flame burn or traffic accident. There were no complications. From our experience, we feel that this new free flap have some advantages, induding vascular anatomy and long pedicle with large diameter and a relatively thin flap with minimal morbidity of donor site.