Primary percutaneous coronary intervention (PPCI) is an emergent percutaneous catheter intervention in the setting of ST elevation myocardial infarction, it is the preferred reperfusion strategy. Aim of the study: Assessment of knowledge and practices of myocardial infarction patients after (PPCI). Study design: A descriptive cross- sectional study research design has been utilized. Setting: the study was conducted at outpatient clinic Cardiovascular, Heart Hospital Assiut University. Subjects: A convenience sample of 150 patients was included in the study. Tools: A structured interview questionnaire including three parts included personal data, patients' knowledge about myocardial infarction, (PPCI)and reported practices Results: It was found that 43,3% of patients their age were younger than 50 year and 77.0% of them were males also it was found that 58.0% of patients had poor knowledge about myocardial infarction and (PPCI). More than three quarters of patients always take food rich in fat. 60.7 % of them never practice any kind of exercise, 83.3% of them were smokers. Conclusion: There was a great lacking of the necessary basic knowledge and practice of studied patients about myocardial infarction after (PPCI). Recommendations: Health education program is needed for patients with myocardial infarction to improve their knowledge and practice regarding their disease