Myocardial infarction is being increasingly reported in younger women. Eleven women younger than 40 years who were admitted for recent myocardial infarction between 1989 and 1993 were studied, Results of this study and of a literature review demonstrated risk factors also found in men (primarily smoking, but also genetic predisposition, dyslipidemia, and arterial hypertension), as well as risk factors specific to women, including oral contraception (particularly in smokers) and peripartal events (toxemia of pregnancy, treatment with adrenoceptor agonists). Selective coronary arteriography usually showed lesions of a single vessel or intact coronary arteries. Although atherosclerosis may be a contributory factor, the frequently normal appearance of the coronary arteries suggests a predominant role of acute thrombosis and/or spasm. The treatment should be the same as in men, except during pregnancy, Female gender may be a factor of adverse prognostic significance.