To measure the prevalence of coronary heart disease (CHD) risk factors in the female partners of men with acute myocardial infarction (AMI). Consecutive incident cases of men under 65 years of age with AMI surviving to 3 months, their female partners and female healthy controls matched for age and marital status drawn from the general population were investigated. One-hundred and seventeen cases of AMI in men under 65 years of age and 89 female partners were identified; 133 age- and sex-matched controls were examined for CHD risk factors. Cigarette smoking was more common among the younger partners (25–44 years of age) compared with controls. A body mass index >28 kg/m2, systolic blood pressure 150 mmHg, diastolic blood pressure >90 mmHg and cholesterol >6.5 mmol/l were all significantly more common in partners compared with controls. In a logistic regression of age, smoking habit, blood pressure, cholesterol and body mass index, based on 89 female partners and 1 32 controls with complete data, body mass index >28 kg/m2 (odds ratio 2.17, 95% Cl 1.11–4.23) and cholesterol >6.5 mmol/l (odds ratio 2,21, 95% Cl 1.08–4.49) were both significantly more common in the female partners compared with controls Women married to men with AMI have a higher frequency of CHD risk factors compared with married women in the general population, consistent with a shared family lifestyle putting both adults at higher risk of CHD. Screening blood relatives in families prematurely affected by CHD is widely advocated; such screening should include partners.