Background: Myocardial Infarction (MI) is a common presentation of ischemic heart disease. Health education programs can improve the outcomes for different chronic conditions. An important mechanism in improving health status for participants in health education programs is the patient self-efficacy. Aim of this study was to evaluate the effect of an educational program on self-efficacy of patients with MI. Subjects & Methods: Research Design: A quasi experimental research design was used. Setting: The study was conducted in cardiac units of Cardiothoracic Hospital and outpatient cardiac clinic at Zagazig University Hospitals. Subjects: composed of fifty adult patients, purposeful selected from both sexes according to inclusion and exclusion criteria. Tools of data collection: Three tools were used to collect the data; interviewing assessment questionnaire, needs assessment questionnaire and self-efficacy scale. Results revealed that, the highest percentage were male more than 50 years, 92.5% having co-morbid disease mainly hypertension. There were statistically significant improvements in patients' knowledge, patients' practice and self-efficacy (p < .001) which continued through follow-up. Conclusion: The study demonstrated statistical significant improvement of patients' knowledge, practices and their self-efficacy in post and follow up program phases compared to pre program phase, but some slight decline occurred in the follow up program phase compared with post phase. Recommendations: Self-efficacy of patient should be more considered and evaluated during the plan for treatment by trained nurse.