The Authors newly designed one of the Myocutaneous Falp modifying the peroneal island flap. This flap involved a part of peroneal muscle and skin on the outer side of leg and pedicle consisting of the peroneal artery and vein as an island flap. It was useful on soft tissue and skin defect of ipsilateral leg or foot region, which area was needed thicker one than simple cutaneous flap. We have treated four patients using this flap and achieved satisfactory results.