Abstract Introduction Despite guidelines recommending referral to cardiac rehabilitation (CR), attendance remains poor. Literature cites a complexity of clinical, psychological and social factors as barriers to CR attendance and, females may attend less than males. Social factors including work commitments, may influence attendance, with many Australian CR programs offered during office hours, making access difficult. The Australian retirement age for females and males differs; (females >60 years and males >65 years). We hypothesised that working-age may influence attendance to CR. Purpose In a CR-referred population this study sought to compare working-age of males and females and the association with CR attendance. Methods Data from 24 country and metropolitan CR services between 2013 and 2015 were linked to 49,909 CR-eligible patients defined as, discharged alive with a primary cardiac-related diagnosis and/or interventional procedure, identified through public hospital administrative data (Figure). Only CR-referred patients were included, with males and females categorised by three age groups: <60, 60–65 and >65 years, comparing attendance in univariate analysis. Adjustment for clinical and psychological (International Classification of Disease-10 Australian Modification mental health diagnostic-related group diagnoses) factors were conducted using multi-logistic regression. Results Between 2013–2015, 15,089 patients were referred to CR with 4,819 <60 years, 1,943 between 60–65 years and 8,327 >65 years. Of referrals a total of 4,286 (28.4%) attended CR, 1134 (35%) of whom were female. Univariate analysis observed total attendance by age group ranged between 26–32%, with females less likely to attend than males (<60 years; 25.3% v 32.2%, p<0.001, 60–65 years; 29.5% v 33.2%, p=0.130 and >65 years; 23.2% v 23.6%, p<0.001). Multivariate analysis observed more attendance in the 60–65 years group compared to <60 years (odds ratio (OR): 1.15 [95% confidence interval [CI]: 1.00–1.32], p=0.036) with females less likely to attend than males (OR: 0.81, [95% CI; 0.70–0.95], p=0.009). No interaction between the working age classification and gender were observed. Conclusion In an Australian cohort, working-age observed no influence on cardiac rehabilitation program attendance, with the period of female retirement age observing a 19% reduction in attendance. Further research on the complexity of factors that may be barriers to attendance is essential to evaluate how to improve cardiac rehabilitation programs to better suit the needs of our cardiac patients. Acknowledgement/Funding Flinders University partnership grant and South Australian Department of Health Local Health Networks