Objective: To determine patients' perceptions of the benefits of participating in outpatient cardiac rehabilitation and the reasons why some decline to take part. Method: Data collected included patients' responses to the self-administrated 'Outpatient Cardiac Rehabilitation Program Evaluation' form, after attending a cardiac rehabilitation program. The evaluation involved analysis of 9 binary and open ended questions. A retrospective study was completed on data collected from January 2010 to December 2015 (6 years) and included 643 adult cases comprising 500 men and 143 women. A between subject t-Test was used to compare patient means before and after attendance of perceived changes to their lifestyle, and overall sense of physical and emotional well-being. Fishers Exact Test was used to compare attendance percentages, gender distribution, and primary diagnosis. Results: Two hundred and seventy nine (43.4%) of the 643 invited patients participated in the cardiac rehabilitation program, while 364 (56.6%) declined, with this result being significantly lower (p < 0.001) than those reported in other Australian locations. The sex distribution of those that participated was 234 (83.8%) males and 45 (16.2%) females while those that declined were 266 (73.1%) males and 98 (23.9%) females. The male prevalence of both attendance and non-attendance was significant (p < 0.001). Patients with a primary referral diagnosis of having a percutaneous coronary intervention and acute myocardial infarction were significantly (p < 0.05) more likely to decline cardiac rehabilitation. Of those who participated, 96.1% indicated they received benefits from attending the cardiac rehabilitation program, with 96.8% identifying significant changes to their lifestyle (p < 0.01) and sense of well-being improvement (p < 0.001) as key benefits, in addition to perceived quicker recovery. According to participants, these positive outcomes resulted from a healthier diet, exercise, better stress management, and support from other patients with similar conditions. The major reasons for declining participation was 'not wanting to attend' (19.3%), 'referred to another hospital service' (10.6%), and 'work related commitments' (7.3%). Conclusion: Considering the reported benefits of attending cardiac rehabilitation, the number of people who decline to attend has important implications for their health and related health system costs related to ongoing disease.