Background: To optimize deformity correction after acetabular osteotomy, low-dose CT is used in preoperative planning when acetabular dysplasia is present. Objectives: This work aimed to assess the usefulness of computed tomography in older children with developmental dysplasia of the hip (DDH) aged 2 to 10 years. This was done preoperatively to identify the site of acetabular deficiency and guide Dega osteotomy and postoperatively to assess the acetabular remodeling and development. Patients and methods: This work was a prospective study that had evaluated certain acetabular parameters using computed tomography before and after Dega osteotomy in 20 patients (24 hips) with DDH who were operated on at Menoufia University Hospital between January 2021 and August 2022. Results: Clinical evaluations showed excellent outcomes in 15 hips (62.5%) and good in 9 hips (37.5%). Radiologically, 16 hips (66.7%) were rated excellent, and 8 hips (33.3%) were good. Significant improvements were observed in acetabular parameters. At the final follow-up the mean anterior acetabular sector angle (AASA) was 52.67 ^o ± 3.10, the posterior acetabular sector angle (PASA) showed statistically insignificant improvement, the mean anterolateral acetabular lip angle (ALAL) was 46.73 ^o ± 2.89, the mean posterolateral acetabular lip angle (PLAL) was 49.50 ^o ± 4.21, the mean acetabular version angle (AV) angle was 15.67 ^O ± 3.10, and the mean center edge angle (CEA) was 34.52^o ± 4.41. Conclusions: CT is one of the crucial investigations in DDH assessment because it can evaluate the hip in different plans. Depending on where it is hinged, the Dega osteotomy may enhance acetabular coverage anteriorly, anterolaterally, and posteriorly.