Background – Cardiac rehabilitation in the weeks following an acute coronary syndrome (ACS) is recommended to reduce patient morbidity and mortality and has been shown to improve patients’ functional capacity and quality of life. The objective was to describe national and regional trends in the rates of patients admitted to cardiac rehabilitation following ACS in France from 2009 to 2021, disparities in admission, and the impact of the COVID-19 pandemic. Methods – All patients hospitalized for ACS in France between January 2009 and June 2021 were selected from the Medical Information Systems Program for Medicine, Surgery, and Obstetrics (PMSI-MCO) of the National Health Data System (SNDS). A hospitalization for cardiac rehabilitation was sought within 6 months following discharge from the index hospitalization for ACS. Standardized cardiac rehabilitation rates were calculated at the national and regional levels for all patients with ACS and stratified by sex, age, and ACS subtypes. Poisson regression models were used to identify factors independently associated with admission to cardiac rehabilitation. Results – In 2019, of the 134,846 patients with ACS, 22% were admitted to cardiac rehabilitation within 6 months of the ACS. In mainland France, these rates ranged from 16% in Hauts-de-France to 31% in Centre-Val de Loire; and were less than 10% in the overseas departments and regions (DROM), with the exception of Réunion. The mean age of patients admitted for cardiac rehabilitation was 62 years (standard deviation, SD=11.7), and the median time between hospitalization for ACS and cardiac rehabilitation was 32 days (95% confidence interval, 95% CI: [10–63]). Factors significantly associated with lower rates of admission to cardiac rehabilitation were female gender, age over 65, the presence of comorbidities, and residence in a disadvantaged municipality or in certain regions. Between 2009 and 2019, cardiac rehabilitation rates increased by 40%, rising from 16% to 22%. These rates increased more among women than among men, but remained significantly lower among women. During the COVID-19 pandemic, cardiac rehabilitation rates dropped. Conclusion – Although on the rise and despite the recommendations and major benefits of cardiac rehabilitation, current rates of admission to cardiac rehabilitation following an ACS remain insufficient in France, particularly for older adults, women, socially disadvantaged individuals, and those living in certain French regions. The decline in cardiac rehabilitation admission rates during the COVID-19 pandemic represents a significant loss of opportunity in terms of prognosis for patients who experienced an ACS in 2020 and 2021. Given the benefits of these programs, it is important to promote universal access to cardiac rehabilitation.