Objectives: To investigate the value of a post-operative gait training program to improve pelvic obliquity (PO) and decrease leg length discrepancy (LLD) for patients with Crowe type I developmental dysplasia of the hip (DDH) undergoing unilateral total hip arthroplasty (THA). Methods: The prospective group consisted of 35 patients who underwent one-stage unilateral THA. Pre- and post-training PO and LLD were measured for the radiological assessment and Harris Hip Score (HHS) was used for the functional assessment. Results: The HHS improved from 55.54
10.61 pre-operatively to 84.97
7.63 after surgery. The mean post-training PO angle for grade 0, grade 1, and grade 2 were 2.66
1.42, 2.94
1.42, and 5.60
1.90, respectively, compared with pre-training values of 1.42
0.58, 4.17
0.90, and 6.96
0.46. The mean post-training LLD for grade 0, grade 1, and grade 2 were 0.83
0.91, 0.56
0.48, and 0.36
0.30, respectively, compared with pre-training values of 0.70
0.23, 1.25
0.90, and 1.46
1.60. Conclusion: Gait training following unilateral THA can improve PO and decrease functional LLD in grade I DDH patients. This method may have moderate success for grade 0 DDH patients and provide limited benefit for grade II patients. Appropriate release of the soft tissues may be required for grade II DDH patients to obtain a better walking gait.