Abstract: Objective: To find out when and how to treat the hip redislocation after open reduction of developmental dislocation of the hip. Methods: Eighteen patients with 18 redislocated hips underwent open reduction. The second procedures were done on the average time 1 year and 3 months after the first open reduction of developmental dislocation of the hip. Fifteen of 18 hips needed acetabular procedures and twelve needed femoral shortening and derotation osteotomy. Results: According to Mckay’s criteria, 8 cases got excellent clinical results,5 cases good result and 5 cases fair result. Xay showed that 8 hips got excellent results, 4 good result and 6 fair result by Severin’s criteria. Conclusion: The best time of surgical management for the hip redislocation after open reduction of developmental dislocation of the hip was one year or so. The procedures still depended on the patient’s age and pathological changes of the hip.