Background: Myocardial infarction (MI), commonly referred to as a heart attack, is a potentially fatal condition that affects a person's physical, mental, and social aspects. It happens when blood flow to a portion of the heart slows or ceases and damaging the muscle. Aim of study: evaluate the impact of a designed nursing protocol on self- efficacy among myocardial infarction Patients. Design: Quasi-experimental research design was utilized to fulfill purpose of the study. Subjects: A purposive sample included (80) adult patients with myocardial infarction. Setting: This study was carried out at Coronary Care Unit (CCU) at Minia University Hospital's. Tools: Three tools were used to gather data, first tool is a structured interview includes two parts (socio-demographic and medical sheet data) second tool is Physical Activity adherence sheet which includes the activity of daily living and range of motion. Third tool is nutrition Adherence sheet. Results: shows that the highest mean score of patients adherence (study group) to physical activity, rang of motion, nutrition post 6weeks and post 12 weeks of protocol implementation with highly statistical significance, Slightly more than half of the studied patients (57.5%) were within the age group of 51–60 years. Three-quarters of them were males (75%). Conclusion: education protocol of MI patient is necessary to achieve an optimum level of self-efficacy regard their adherence to physical activity, Rang of motion, nutrition. Recommendations: Replication of this study on larger probability sample is highly recommended.