Introduction: Cardiac rehabilitation (CR) has been shown to decrease mortality and morbidity, improve the control of risk factors and the quality of life of patients with coronary artery disease. However, the elderly are underrepresented in most studies and in real-life CR programs. Our goal was to evaluate the impact of CR after an acute coronary syndrome in the elderly population. Methods: A cutoff of 65 years was used to dichotomize age. Our main focus was on the effects of ambulatory supervised exercise training on several surrogate markers, namely total cholesterol, low- and high-density lipoprotein cholesterol, triglycerides, body mass index, fasting glucose, glycated hemoglobin, probrain natriuretic peptide, International Physical Activity Questionnaire score, maximal exercise capacity, chronotropic response index and heart rate recovery. We evaluated those variables at the beginning and at the end of phase II of the CR program (after 3 months) and repeated the treadmill test at 12 months. Results: A total of 548 patients with a recent acute coronary syndrome were enrolled; 37% were 65 years old or older. Both age groups had a statistically significant improvement in all the evaluated parameters. Interestingly, at 12 months both groups maintained the improvement in functional capacity seen immediately after 3 months. Conclusions: The benefits of CR in terms of functional capacity, metabolic profile and other prognostic parameters were significant in both younger and older patients. Therefore, all eligible patients should be referred to CR programs, irrespective of age.