It has been generally agreed that most fractures of the humeral shaft are best treated non-operatively although occasionally there are indications for primary operative treatment. Recent advances in internal fixation techniques and instrumentation have led to an expansion of surgical indications, and operative treatment produces higher rates of nonunion, infection and other associated complication when compared with closed treatmet techniques. Because of the significant morbidity of the operative treatment, closed intramedullary fixation techniques that provide stability of the fracture site without opening and reduce the postoperative complications, were developed. In this paper we document forty two fractures of the humeral shafts that were treated by functional bracing(Group I: 24 cases) and intramedullary fixation with functional bracing(Group II: 18 cases) between October, 1982 and August, 1986. And the obtained results were as follows: 1. The everage healing time was 9 weeks in the Group I, and 11 weeks in the Group II . 2. The non-union has not been encountered in the Group I, but non-union and delayed union were 4 cases (22.2%) in the Group II. 3. The complication rate was 9 cases(37.5%) in the Group I, and was 12 cases(66.7%) in the Group II, but deep infection did not occured in all cases. 4. The residual angulation more than 5 degrees was 20 cases(83.3%) in the Group I, and was 2 cases(11.1%) in the Group Il. However the results of the group Il were inferior ot the group I, of more proper selection of the patients, more accurate technique and adequate type of nails have been used, the better results will be taken.