A study was undertaken to determine whether women who suffer a myocardial infarction in spite of the low frequency in this sex, are more heavily burdened by coronary riskfactors than other women The multivariate risk, based on cholesterol level, systolic blood pressure, and smoking habits, in the women with infarction was very similar to that in the men with myocardial infarction. There was no major difference in risk between pre-and postmenopausal women. A higher prevalence of diabetes mellitus in the women with infarction compared with the general population could not explain their increased risk for myocardial infarction. Thus, other factors must be operating in addition to the traditional risk factors.The incidence of myocardial infarction is higher in men than in women. From a Myocardial Infarction Register, we found the incidence to be about 6 times higher in men than in women in the age group 45 to 54 years (Elmfeldt et al., 1975a). The prevalence of angina pectoris as determined by a questionnaire was, however, similar in the two sexes (Bengtsson, 1969). Because of the low incidence of myocardial infarction in women, few population studies have been able to give an indication of prospective risk factors for this disease in women. In most communities, the only way of finding risk factors in women would be to perform well-designed case control studies.In the Framingham study (Kannel and Castelli, 1972), it was found that the same risk factors seem to operate in women as in men. It has been found that the mean age at the menopause was somewhat lower among women with myocardial infarction than among women in general population samples of similar age (Bengtsson, 1973;Kannel et al., 1975). In a report on myocardial infarction women several of the patients were still menstruating (Bengtsson, 1973), suggesting the protective effect Received for publication 14 April 1977 of the female hormone pattern can be nullified. A question of relevance in this connection is whether those women who suffer a myocardial infarct, but who are still menstruating, are more heavily burdened by coronary risk factors than other women and men of similar age.The present paper reports some data concerning multivariate risk prediction based on serum cholesterol level, systolic blood pressure, and smoking habits, with the aim of comparing the risk factor profile in the male and female population and in men and women who had suffered a myocardial infarct. Prospective data from a population study in men were available (Wilhelmsen et al., 1973).