We report 41 patients with myocardial infarction who were less than forty years old and that had been studied by coronary angiography. 97.5% were male mostly in their thirties. Coronary risk factors in this group were similar to the old one; excepting for mental stress present in 75% of our patients. There was not predominant infarction site. We observed different disturbances of the cardiac rhythm but no patient had congestive heart failure or cardiogenic shock. Mortality due to the infarct itself was none .61% of the cases had univascular lesions or normal coronary angiography and only 12% had trivascular lesions. The patients with normal coronary angiography had no significant difference in the mayor coronary risk factors and in our group we found patients with arterial hypertension, hyperlipidemia, cigarette smoking and obesity. We suggest that mental stress is an important coronary risk factor; the evolution of these patients is favorable and the mortality is low as compared with previous reports.