Objective: This study examined the internal and external validity of the Memory Complaint Questionnaire (MAC-Q), a brief measure of subjective memory complaint in people with normal cognitive function. Study Design and Setting: The Study of Health Outcomes in Aircraft Maintenance Personnel was a retrospective cohort study investigating the association between aircraft fuel tank deseal/reseal activities and health status in Royal Australian Air Force personnel. Crosssectional comparison tests included measures of executive functioning, psychomotor speed, attention/working memory, newlearning/memory, depression, and anxiety. An adjusted regression analysis accounted for confounders including age, dates of posting, rank, education, alcohol use, tobacco use, and affective status. Results: Eight hundred seventy-nine participants completed the MAC-Q. Although the MAC-Q tested as highly reliable and internally valid, it was highly associated with affective status and was only associated with Digit Symbol Coding after adjustment for depression/anxiety. Conclusion: The MAC-Q is greatly influenced by affective status but not memory performance. It is probably not useful as a specific screen of memory complaint for general population research.