Supracondylar fracture of the humerus is the most common fracture of the elbow in children. Early accurate reduction is very important to obtain good results. Authors tried to reduce the fracture accurately under the concept of intact hinge mechanism. Forty-five displaced supracondylar fractures which were not able to be reduced by closed method were admitted for open reduction at our department from April 1981 to October 1985. They were analysed clinically. The result are as follows: 1. The patient age ranged from 3 to 14 years; 16.2% were between 7 and 8 years. 70.3% were boys Left humerus was affected in 70.3% of all cases. 2. The most common cause of fracture was falling down from height. 94.6% of fractures were extension type. The severity of displacement in 34 patients(90.2%) were grade III or 1V of Holmberg classification. 3. Only in 2 patients cubitus varus deformity was observed as residua and among the patients who were followed more than one year, only 2 had about 10 degrees of limitation of elbow motion. 4. In Holmberg’s grade II, III, IV group, 22 cases(100.0%) of the both side pinned and 12 cases (80.0%) of one side pinned showed excellent or good results. Therefore, both side pinning could have contributed in obtaining more accurate reduction. 5. According to Mitchell and Adams' Criteria, 34 cases(91.9%) had satisfactory results.