© 2022 Turkish Association of Trauma and Emergency Surgery.BACKGROUND: Harris hip score (HHS), modified HHS (MHHS), and Oxford hip score (OHS) were designed to determine the functional outcomes after primary total hip arthroplasty (THA). The aim of this study was to evaluate the correlation between MHHS, HHS, and OHS in different populations of arthroplasty such as primary THA, revision THA, THA for Crowe Type IV developmental dysplasia of the hip (DDH), and hip hemiarthroplasty (HA). METHODS: A total of 399 patients (254 females and 145 males) that included 128 cases of primary THA, 36 of revision THA, 200 of HA, and 35 of THA with femoral shortening osteotomy with a minimum of 24 months of follow-up were included. HHS, MHHS, and OHS were calculated for each patient and the correlation between theses scores was evaluated for each subgroup. RESULTS: The overall mean age was 67.5±14.3 years. The mean HHS, MHHS, and OHS were 74.9±17.9, 75.7±18.7, and 38.7±12.5, respectively. A very strong correlation was observed between HHS and MHHS (r=0.995, p=0.000) as well as between HHS and OHS (r=0.845, p=0.003) in the general study population. In subgroup analysis, there was a very strong correlation between HHS and MHHS in primary THA, revision THA, THA in hip HA, and Crowe Type IV DDH groups (r=0.984, p=0.000; r=0.977, p=0.000; r=0.984, p=0.000; and r=0.995, p=0.000; respectively). However, there was a significant correlation between HHS and OHS in these groups except revision THA group (r=0.851, p=0.023; r=0.587, p=0.069; r=0.989, p=0.002; and r=0.965, p=0.000; respectively). CONCLUSION: This is the first study to investigate the usefulness of MHHS and OHS in hip HA and THA in patients with Crowe Type IV DDH. Our findings suggest that MHHS and OHS are useful for evaluating functional outcomes with HA, primary and revision THA, and THA with femoral shortening osteotomy for Crowe type IV DDH.