Background Exercise therapy has been recommended as a core element for the prevention of coronary heart disease (CHD). However, the independent impact of exercise therapy remains unclear. Objective The aim of this study was to assess the effects of exercise therapy compared with no exercise control in patients with CHD. Methods We searched 8 electronic databases from January 2000 to March 2020. Randomized controlled trials with at least 6 months of follow-up that evaluated the effects of exercise therapy on hospital admissions, health-related quality of life (HRQoL), mortality, and morbidity in adults with CHD were included. Two reviewers independently screened records for eligibility, extracted data, and assessed risks of bias using the Cochrane tool. Meta-analyses were conducted using the random-effects model. Results We included 22 randomized controlled trials involving 4465 participants. Compared with no exercise control, exercise therapy reduced all-cause hospital admissions (10 studies; risk ratio, 0.46; 95% confidence interval, 0.25-0.83; I-2 = 64%) and cardiovascular mortality (9 studies; risk ratio, 0.44; 95% confidence interval, 0.22-0.89; I-2= 0%) across all studies reporting these outcomes at their longest follow-up. Eight of 14 studies that assessed HRQoL observed a significant improvement in at least 1 domain or overall HRQoL with exercise therapy compared with control. There were no significant reductions in cardiovascular hospital admissions, all-cause mortality, incidence of myocardial infarction, or revascularization. Conclusions This review shows the independent benefits of exercise therapy in reducing all-cause hospital admissions and cardiovascular mortality for adults with CHD.