BACKGROUND:Valid and reliable questionnaires to assess hip and groin pain are lacking. The Hip and Groin Outcome Score (HAGOS) is a valid and reliable self-reported measure to assess symptoms, activity limitations, participation restrictions and quality of life of persons with hip and/or groin complaints. The purpose of this study was to translate and cross-culturally adapt the HAGOS into Dutch (HAGOS-NL), and to evaluate its internal consistency, validity and reliability. METHODS:Translation and cross-cultural adaption of the Dutch version of the HAGOS (HAGOS-NL) was performed according to international guidelines. The study population consisted of 178 adult patients who had undergone groin hernia repair surgery in the previous year. All respondents filled in the HAGOS-NL, the SF-36, and the SMFA-NL for determining construct validity of the HAGOS-NL. To determine reliability, 81 respondents filled in the HAGOS-NL after a time interval of two weeks. RESULTS:Factor analysis confirmed the original six-factor solution of the HAGOS. Internal consistency was good for all the subscales of the HAGOS-NL. High correlations were observed between the HAGOS-NL and the SF-36 and SMFA-NL, indicating good construct validity. The HAGOS-NL showed high reliability, except for the subscale Participation in Physical Activities which was moderate. CONCLUSIONS:The HAGOS was successfully translated and cross-culturally adapted from English into Dutch (HAGOS-NL). This study shows that the HAGOS-NL is a valid and reliable instrument for the assessment of functional status and health-related quality of life in patients with groin complaints.