Assessing personality in research can be of importance, especially due to the potential relationship between different personality traits and the manifestation of symptoms in different clinical conditions. Therefore, it is important to have valid and reliable tools that allow for the assessment of personality traits. In this study, the aim was to translate and culturally adapt the Big Five Inventory (BFI) to the Danish language. A dual panel approach, consisting of a 4-person bilingual panel and an 8-person panel with laymen, was used to translate and culturally adapt the questionnaire. A third 9-person panel consisting of people with different medical diagnosis was used to assess the face validity. Internal consistency (Cronbach's α) and test-retest reliability (intraclass correlation coefficients (ICC)) were tested amongst 96 subjects. The translated version demonstrated adequate internal consistency (0.66-0.84) and good-excellent test-retest reliability (0.86-0.95). The smallest detectable change is between 1.13-1.70 for the five subscales. Both the healthy and patient panels of laymen considered the questionnaire too long. This translated version of the Big Five Inventory demonstrated high to very high test-retest reliability and, for most parts, an acceptable internal consistency. The construct validity was however different from versions translated into languages geographically and culturally similar to Danish. Assessing the Big Five personality traits in Danish populations can be valuable for many reasons, e.g. when assessing people in pain in both clinical and experimental settings. Improved knowledge of the underlying driver of pain conditions is important. Here, understanding how personality may interact with pain can help researchers and clinicians.