Introduction: Developmental Dysplasia of the Hip (DDH) is the current definition which includes a wide range of severity, from mild acetabular dysplasia without hip dislocation to hip dislocation. DDH is a disorder of abnormal development resulting in dysplasia, subluxation, and possible dislocation of the hip secondary to capsular laxity and mechanical instability. Purpose: The study of the functional result of the surgical treatment in adults with DDH. Material and methods: Retrospective study that lasted from March 2015 to March 2020. Mean outpatient follow-up was at least 9 months and patients with follow-up under 6 months were excluded. Outcomes were measured using Harris Hip Score in 3 and 6 months postoperative. Results: This study included 22 patients (14 females and 8 males) with a mean age of 54.2 years. The majority of patients have fair Harris Hip Score at 3 months post-op and are fully functional in 6 months. Conclusions: DDH is the most common hip disorder in children and it is most common in females. The left hip is more commonly involved and it is bilateral in 20% of the cases. DDH is among the most common causes of premature hip arthritis. DDH is the main cause of THA in young people (21 – 29%). The surgical treatment of DDH in adults is challenging and is crucial to place the acetabular component in the true acetabulum to restore the normal hip center of rotation and biomechanics.