Twenty-seven adults who had a closed fracture of both bones of the forearm were managed with plate in twenty-four radial and twenty-three ulnar fracture. and with intramedullary nailing in three radial and four ulnar fractures. And were followed for a mean three years and two months(range, one year to six years). Standard anterioposterior and lateral radiographs were made of both forearms, and evaluated bone union that was qualified by measurement of the amount and location of the maximum radial bow in the relation to the contralateral normal ram. The functional outcome was assessed with rating system of Anderson, which is based on union of the fracture and rotation to the forearm, also with measurement of grip strength. Overall rate of union for the radius was 92.5 per cent and for the ulna 96.2 per cent. Average time to union was 10.4 weeks in the radius and 10.3 weeks in the ulna. Twenty-three patients(84%) had an excellent, good, or acceptible functional results, according to the criteria of Anderson. At follow-up, the mean and standard error for motion of the elbow from 64.0±4.1 of pronation to 74.3±4.2 supination. Seventeen patients(63%) had a grip strength that was more than 80 per cent of that of the contralateral side. Mean maximal radial bow was 15.1±0.4 millimeter and mean location of radial bow was 61.2±1.1 per cent in the normal arm. There was good or excellent rotation of the forearm, the rotation was close to where it was in the normal extremity. When five radial and three ulnar transverse fractures which were treated with less than five-hole plate, radiographic union was delayed(mean 13.3 weeks) and less satisfactory restoration of the function were obtained. However eleven radial and nine ulnar transverse fractures which were treated with more than six-hole plate were all united(mean 10.2 weeks) and acceptible restoration of the function were obtained Overall, there were three nonunions(two radial and one ulnar fracture), and one infection. Restoration of the normal radial bow was related to functional outcome. A good functional result was associated with restoration of the normal amount and location of the radial bow. Plating with more than six cortex secured by screws on each side of the fracture, provided a successful method for obtaining union and optimum function after fractures of the foream.