OBJECTIVE: To survey the cardiovascular complications induced by cardiac monitoring exercise during 10 years of our cardiac rehabilitation (CR) clinic and report on the safety of monitoring exercise training for early hospital-based CR. METHOD: All cardiac patients who participated in our exercise program from January 2000 through December 2009 were recruited as study subjects. We stratified the exercise risks of cardiac events and conducted the monitoring exercise with individualized prescriptions. We measured all cardiac complications, including death, symptoms, abnormal hemodynamic responses, and electrocardiogram (ECG) abnormality during exercise training, for 10 years. A total of 975 patients (68% male; mean age, 58.9+/-10.6) were included in this study. Initial indications for CR were recent percutaneous transluminal coronary angioplasty (PTCA) (75%), post-cardiac surgery (coronary bypass graft, 13.2%), valvular surgery and other cardiac surgery (4.2%), and others (7.6%). RESULTS: The study population underwent 13,934 patient-hours of monitoring exercise. No death, cardiac arrest or acute myocardial infarction (AMI) occurred during exercise (0/13,934 exercise-hours). Fifty-nine patients experienced 70 cardiovascular events during the 13,934 exercise-hours (1/199 exercise-hours); there were 17 cases of angina only (1/820 exercise-hours), 31 cases of ECG abnormalities only (1/449 exercise-hours), 12 cases of angina with ECG abnormalities (1/1,161 exercise-hours), and 10 cases of abnormal hemodynamic responses (1/1,393 exercise-hours). CONCLUSION: Early hospital-based CR is safe enough that no death, cardiac arrest or AMI occurred during the 13,934 patient-hours of monitoring exercise. However, risk stratification for exercise-induced cardiovascular events, proper exercise prescriptions, and intensive ECG monitoring are required prior to initiation of the monitoring exercise.