There are various perative methods for the treatment of neglected Monteggia fracture-dislocation. ut, it is difficult to obtain good results by the onlyone operative method in the adolescent period. We reported two patients for the neglected Monteggia fracture-dislocation in adolescent period who were treated by the combined operative treatment. The combined operative method was, in regular sequence, the ulnar osteotomy, the fibrous tissus removed in the humeroradial joint, radial head reduction, Bell-Tawse annular-ligament reconstruction and fixating the radial head to the capitellum with the K-wire with neutral position. Finally, plate fixation in ulnar osteotomy site was done. After 3 weeks, we removed the K-wire and performed active ROM exercise. The clinical results were evaluated by Bruce scale at the follow-up 15 months and 53 months. The results were satisfactory without complications. So we canvass for this combined method about neglected Monteggia fracture-dislocation in adolescent period.