Epidemiological studies show that 1 in 5 Australians aged 18-24 are diagnosed as having an alcohol use disorder (AUD). However, there is evidence to suggest that young adults may interpret the diagnostic criteria differently to older adults. The current study aimed to validate the alcohol use disorder criteria in younger populations through the use of novel cognitive interviewing techniques. Results showed that while young adults understand some of the AUD diagnostic criteria as intended (e.g. tolerance), other criteria are misinterpreted, resulting in an over-estimation of the prevalence of alcohol use disorders in this age group.