Abstract Background: Myocardial infarction MI is the leading cause of death all over the world. One of the most important risk factors for MI is diabetes mellitus especially if presented with other risk factors as smoking, hypercholesterolemia and hypertension. The higher level of HgA1c is associated with increasing complications of MI. Aim of Study: This study aimed to study the prevalence of MI in young diabetic patients (20-39 years) living in North Sinai governorate. Patients and Methods: This study was carried-out on 100 patients aged 20-39 years, patients suffering from diabetes mellitus either Type 1 or type 2 or, recently diagnosed DM or long time diabetic patients, on oral hypoglycemic medica-tions or insulin treatment. All patients were subjected to standard 12 lead electrocardiogram (ECG), full echocardiog-raphy and full laboratory investigations. Excluded from the study were patients with ischemic heart disease diagnosed by history, cardiac enzymes, ECG and/or echocardiography. All patients underwent the following, full history, Chest pain analysis, ECG, echocardiographic, evidence of gross segmental wall motion abnormality. Results: The study indicated that diabetes increase the prevalences of myocardial infarction. Also, the results indicated that dyslipidemia, hypertension, and smoking were risk factors for myocardial infarction, The main symptoms of cardiac infarction includes chest pain. The best methods of diagnosis includes clinical presentation of TCP, ECG, and increasing level of cardiac troponin with increasing level of HgA1C, with increasing complications of MI. Conclusion: The prevalence of myocardial infarction in young diabetic patients (20-39 years) was 17% and the main symptoms of cardiac infarction was typical chest pain. The higher level of HgA1c was associated with increasing com-plications of MI as HF.