PURPOSE: The purpose of this study is to document the results of the interlocking nailing of the humerus fractures which is still controversial. MATERIALS AND METHODS: Twenty three cases of interlocking intramedullary nailing was done. 13 nails were inserted through the shoulder, 10 nails through the olecranon fossa. We used a closed technique for the 22 cases of the nailing. RESULTS: Most patients who had antegrade nailing complained of shoulder pain. The bony union was obtained in 8 patients(61.5%) with antegrade nailing patients, somewhat high rate of nonunion compared to other methods of treatment. Criticism of the procedure is because of the trauma that can occur to the rotator cuff and possible impingement syndrome, which can occur after antegrade insertion. As for the retrograde nailing patients, the union rate was 90%, higher than that of antegrade nailing patients, but without statistical significance. Fracture propagation(3 cases), limitation in elbow extension(1 case) and rotational deformity(1 case) were occurred in retrograde nailing patients. CONCLUSION: Though interlocking intramedullary nailing are an attractive alternative for humeral fracture stabilization because of the limited surgical exposure, there must be further considerations for the insertion site problems and improvement in bony union rate.