Fracture of the ankle is one of the most common fractures. Usually medial malleolar fractures, when non-displaced or minimally displaced, have been treated by closed reduction and cast immobilization for long period, so stiffness and osteoporosis of ankle were frequently inevitable. We investigated the result of percutaneous pinning or screw fixation and early mobilization in the treatment of medial malleolar fracture of the ankle. With clinical and radiological data, authors analysed 17 patients(17 ankles) who were treated with closed reduction and percutaneous pinning or screw fixation between August 1991 and May 1997. and following results were obtained. One case of pin site infection was noted and no nonunion or loss of fixation was identified and average duration of bone union was 12 weeks. According to Burwell's protocol, the good result are 16 cases, the fair is 1 case and the poor result is not observed. From the viewpoint of rehabilitation, authors consider percutaneuos pinning is an excellent plan of treatment of medial malleolar fractures, when non-displaced or minimally displaced.