To explore the possibility of a one stage restoration of protective sensation and finger flexion after electrical burn of the hand, 5 patients with electrical injuries at the wrist were treated by a new free composite flap, originating from the medial lateral crural skin flap. This flap can repair skin, blood vessels, tendons, and nerves in a one-stage procedure. The harvest of the medial lateral crural flap is described. The posterior tibial vessels provide the arterial supply. The perforators to the flap and the branches to the plantaris tendon and the sural nerve were preserved, and the nerve and tendon were kept within the flap by careful dissection of the crural fascia. At the same time, 3 to 4 tendons of extensor digitorum longus were inserted into the layer between superficial and profundus crural fascia. Thus, blood vessels, nerves, and tendons were combined into the flap before transplantation. The composite flap was then transplanted into the recipient site of the injured hand to repair the complex defects in a single operation. Flexion and extension function of the fingers was evaluated. Sensory function was tested by the standards recommended by the British Medical Research Council System for evaluating sensibility. Follow-up ranged from 18 to 24 months. Results revealed all flaps survived. The flexion distance from tip to palmar crease and extension distance from tip to horizontal level of 3 patients were 4 to 5 cm and 3 to 4 cm, respectively. At 6 months, 2 patients improved from 6 cm and 5 cm to 4 cm and 4 cm, respectively. The sensation reached to S2 level, and skin temperature rose. The medial lateral crural composite flap is an ideal, one-stage method to restore protective sensation and finger flexion for advanced-stage patients who have suffered severe high voltage electrical injuries in the wrist.