Abstract: [Objective] To investigate the feasibility and clinical efficacy of surgical therapy without ulnar osteotomy for Bado type I old Monteggia fractures in children. [Methods] A retrospective study was conducted on 29 children who had Bado type I old Monteggia fractures treated surgically involving radial head reduction and internal fixation without ulnar osteotomy in our hospital from September 2016 to September 2021. The clinical and imaging data were evaluated. [Results] All patients were successfully operated without perioperative complications such as vascular and nerve injury and followed up for a mean of (16.2±7.4) months. With time elapsed preoperatively, 12 months postoperatively and the last followup, the elbow HSS score [(84.0 ±5.3), (92.1±3.4), (93.3±2.6), P 0.001] and elbow maximal flexion ROM [(114.0±11.8)°, (139.0±2.4)°, (139.4±1.9)°, P 0.001] were significantly increased, while the forearm maximal pronation ROM was significantly decreased (P＜0.05), and the forearm maximal supination ROM remained unchanged significantly (P＞0.05). During the followup, there were no late complications such as recurrence of radial head dislocation, elbow stiffness and elbow valgus. Radiographically, all radial axes passed through the center of the humerus postoperatively, and the ulnar deformity angle decreased significantly over time [(4.6±1.4)°, (2.5±0.8)°, (2.1±1.0)°, P＜0.001]. [Conclusion] Surgical therapy without-ulnar osteotomy is feasible for Bado type I old Monteggia fracture in children with satisfactory clinical results