Background: Athletic Identity is a theoretical term describing the degree of which a person identifies with the role as an athlete and this reflects how an athlete thrives. The most acknowledged way to quantify athletic identity is the Athletic Identity Measurement Scale (AIMS) which later have been revised to AIMS-Plus by Cieslak (2004). This study aims to create and validate a Danish version of AIMS-Plus for the purpose of quantifying the well-being of student athletes in special sports classes in the Danish public schools. Method: The AIMS-Plus questionnaire from Cieslak (2004) was translated forth and back from English to Danish to create the first Danish version without theoretical compromise in regards of athletic identity and AIMS-Plus. The questionnaire was piloted on a small sample (n=15) of identical audience, as the targeted audience, who was afterwards debriefed to identify issues understanding the questions. A final version of the questionnaire was then created and applied to a test-retest method design: 118 student athletes in special sports classes in a Danish public school answered the questionnaire twice with 19 days in between. The results were analyzed with a paired T-test. Results: A significant positive correlation between the overall athletic identity in the first test (T1) and the second test (T2) was found (r= .785, p< .001), despite a significant difference between these two tests (p=.028). A similar protocol was applied for the five subscales Positive affective, Negative affective, Self-identity, Social identity and Exclusivity, all showing a strong correlation between T1 & T2 as well. Furthermore, Cohen’s d effect size showed that a small, trending towards zero, effect was found between T1 & T2. Conclusion: This study found the developed questionnaire to be both a valid and reliable method to quantify athletic identity in the targeted group of student athletes in special sports classes in the Danish public schools.