Coronary heart diseases are leading causes of death worldwide. Improvements in physical activity behavior and cardiac self-efficacy are useful to adopt a healthy lifestyle and to promote person-centered care in practice. Purpose: to examine the effect of motivation based nursing intervention on physical activity and cardiac self- efficacy among patients with coronary heart diseases. Design: A quasi-experimental design (study-control group) was used. Setting: The study conducted at the cardiology outpatient clinics in Abo Bakr Elsedik clinics for health insurance at Shebin El-Kom, Menoufia governorate, Egypt. Sampling: A purposive sample of 370 (75.1% adults and 24.9% elderly) patients were chosen and equally divided to study-control groups. Instruments: Structured interviewing questionnaire included sociodemographic characteristics, medical data and anthropometric measurements, International physical activity questionnaire and Cardiac self-efficacy questionnaire. Results: Motivation based nursing intervention assisted in increasing the physical activity levels and cardiac self-efficacy score; the level of high physical activity among study group increased from 13.0% on pre intervention to 38.9% on post intervention. Also, mean score of cardiac self-efficacy on post intervention was 28.86 ± 8.6 of the study group compared to 20.9 ± 6.6 of the control group. Furthermore, a statistically significant difference was present between adults and the elderly study patients regarding the overall mean score of physical activity post intervention. Conclusion: Motivation based nursing intervention had a considerable significant positive effect on the levels of physical activity and cardiac self-efficacy score among adults and elderly patients. Recommendation: Motivation based nursing intervention should be incorporated into routine care that is designed for both adults and elderly patients with coronary heart diseases.