Background: Hip and groin pain or symptoms is a recurrent musculoskeletal complaint among young and active individuals. It is important to objectively measure functional limitations using patient-related outcomes that have been validated in the language of the target population. Objectives: To perform a cross-cultural adaptation and to evaluate the measurement properties of the Hip and Groin Outcome Score (HAGOS) for the Brazilian population. Methods: We adapted the HAGOS to Brazilian Portuguese and evaluated the following measurement properties: internal consistency, test–retest reliability, measurement error, and structural and construct validity. The sample recruited consisted of active individuals between 18 and 55 years of age with long standing hip and groin pain and individuals who participated in sports with high physical demand of the hip and groin region. Results: A total of 103 athletes and physically active individuals of both sexes participated in this study. The HAGOS was successfully translated and culturally adapted to the Brazilian population. Factor analysis confirmed that the HAGOS consists of six subscales. The HAGOS-Br showed good internal consistency. The CFA revealed a Cronbach's alpha for the HAGOS subscales ranging from 0.86 to 0.96, test-retest reliability was substantial, with intraclass correlation coefficients ranging from 0.81 to 0.94 for the six subscales and an acceptable measurement error (standard error of measurement [SEM]=5.43–11.15 points; and smallest detectable chance [SDC]= 16.71–30.9 points). Good construct validity existed with more than 75% of the pre-defined hypotheses being confirmed. No ceiling or floor effects were observed. Conclusion: The HAGOS-Br showed to be equivalent to the original version with adequate validity and reliability properties.