Models of second-phase cardiac rehabilitation (CR) following myocardial infarction (MI) differ across countries. The aim of this study was to compare outcomes in MI survivors participating in outpatient and inpatient CR programs. All patients hospitalized for acute MI in Poland between October 2017 and December 2018 (n = 96,634) were included in the study. Among them, 4411 patients were referred to and commenced outpatient CR, whereas 11,626 patients started inpatient CR within 30 days following discharge. The mean follow-up period was 332.8 ± 128.1 days. Younger age, male sex, and a history of cancer were associated with a higher probability of participating in outpatient CR, whereas diabetes, heart failure, chronic kidney disease, chronic obstructive pulmonary disease, ST-elevation MI, and myocardial revascularization were associated with a lower likelihood of outpatient CR participation. Participation in outpatient CR was linked to a reduced risk of all-cause mortality, in both univariable (hazard ratio [95% confidence interval]: 0.37 [0.26-0.51]) and multivariable analyses (0.53 [0.38-0.74]). Outpatient CR was also associated with a lower risk of death, MI, or stroke (0.57 [0.48-0.67] in univariable analysis and 0.72 [0.61-0.84] in multivariable analysis), as well as a lower risk of death or cardiovascular hospitalization (0.78 [0.73-0.84] and 0.85 [0.80-0.91], respectively). Outpatient CR following MI tends to occur alongside a better prognosis compared to inpatient programs.