In order to estimate whether women with polycystic ovary syndrome (PCOS) have an increased risk of developing myocardial infarction, a risk factor model was applied on 33 women with PCOS and 132 age matched referents. The risk factor model was established from independent risk factors for myocardial infarction in a prospective population study of 1462 women in Göteborg, Sweden. The independent risk factors were age, manifest hypertension, manifest diabetes mellitus, central obesity measured as increased waist to hip circumference ratio and serum triglyceride concentration. A considerably increased risk (relative risk of 7.4) of developing myocardial infarction was observed for women with PCOS compared to age-matched referents. Since the risk factors include variables correlated to obesity, the results indicate that advice on dietary restriction is an important part of the treatment once the diagnosis is established.