Treatment of DDH in walking-age children often resulting in persistent or recurrent hip dysplasia, AVN and/ or loss of reduction. The incidence of secondary procedures in this age group after closed or open reduction of the hip in DDH varies from 38% to 80% in longterm studies. The goal of this study was to determine the factors that will predict poor results in walking-age children with DDH.The study was a retrospectively study of 25 walking children with late DDH (22 female and 3 male) treated with closed or open reduction of the hips. The data were collected from medical records and radiographs. Tonnis and Severin classifications were used to evaluate the condition of the hips. Fisher exact test and student t-test were used to evaluate the factors related to the poor result.Age > 28 months and > 30 months at the reduction is a factor resulting in poor results evaluated by Tonnis and Severin classification (p = 0.007), and (p = 0.008). Acetabular index (AI) and Center-edge angle (CE) at the time of index surgery are not statistical significant causing the poor results. Bilateral or unilateral of DDH are not statistical significant to cause poor results.From our study, age at presentation is the most important factor predicting poor results in walking DDH, age > 28 months at presenting leading to secondary procedure and poor Tonnis and Severin Grades. National Health Policy for Hip Screening is the most important for early detectoing of children with DDH to improve the outcome and prevent the children from multiple operations.