Background: The Hip disability and Osteoarthritis Outcome Score (HOOS) has been used for the evaluation of patients who have hip osteoarthritis (OA). It is one of the most frequently used instruments for the follow-up of patients operated on for total hip arthroplasty in different national registries. The purpose of this study was to carry out the transcultural adaptation and validation of the Chilean version of the HOOS questionnaire in patients who have hip OA. Methods: The translation and cross-cultural adaptation process were based on international guidelines to obtain a Chilean version of the HOOS questionnaire. The Chilean version was evaluated in the pretest phase and then in the validation phase with patients in the outpatient setting, from patients who had initial OA to patients who had end-stage disease waiting for surgery. We assessed the psychometric properties as convergent validity, evaluating correlations with the Short Form 12 Health Survey (SF12) questionnaire and the World Health Organization Disability Assessment Schedule 2.0 tool; structural validity by conducting a confirmatory factor analysis; and internal consistency using Cronbach's alpha. Results: There were 30 outpatients who participated in the pretest phase and 111 in the validation phase. There was a positive correlation between the HOOS score in the dimensions of activities of daily living, pain, and symptoms with the physical dimension of the SF12 (r > 0.7; P < 0.001). In the same way, the HOOS quality of life item was correlated with the mental dimension of the SF12 (r = 0.51; P < 0.001). The World Health Organization Disability Assessment Schedule 2.0 tool had a moderate negative correlation with all the HOOS dimensions (P < 0.001). Confirmatory factor analysis confirmed good construct validity. Cronbach's alpha was 0.97 for the global questionnaire. Conclusions: The Chilean version of the HOOS questionnaire showed adequate validity and reliability, with adequate psychometric properties. This could have relevance in the evaluation and treatment of patients who have hip OA and in the evaluation of the results of patients undergoing total hip arthroplasty.