CONTEXT AND OBJECTIVE The Nonarthritic Hip Score (NAHS) is a clinical evaluation questionnaire that was developed in the English language to evaluate hip function in young and physically active patients. The aims of this study were to translate this questionnaire into the Brazilian Portuguese language, to adapt it to Brazilian culture and to validate it. DESIGN AND SETTING Cohort study conducted between 2008 and 2010, at Universidade do Estado do Rio de Janeiro (UERJ). METHODS Questions about physical activities and household chores were modified to better fit Brazilian culture. Reproducibility, internal consistency and validity (correlations with the Algofunctional Lequesne Index and the Western Ontario and McMaster Universities Arthritis Index [WOMAC]) were tested. The NAHS-Brazil, Lequesne and WOMAC questionnaires were applied to 64 young and physically active patients (mean age, 40.9 years; 31 women). RESULTS The intraclass correlation coefficient (which measures reproducibility) was 0.837 (P < 0.001). Bland-Altman plots revealed a mean error in the difference between the two measurements of 0.42. The internal consistency was confirmed through a Cronbach alpha of 0.944. The validity between NAHS-Brazil and Lequesne and between NAHS-Brazil and WOMAC showed high correlations, r = 0.7340 and r = 0.9073, respectively. NAHS-Brazil showed good validity with no floor or ceiling effects. CONCLUSION The NAHS was translated into the Brazilian Portuguese language and was cross-culturally adapted to Brazilian culture. It was shown to be a useful tool in clinical practice for assessing the quality of life of young and physically active patients with hip pain.