OBJECTIVE: Vascular calcification holds promise as a useful cardiovascular risk maker. Our objective was to examine the association between breast vascular calcification and risk of cardiovascular disease (CVD) outcomes. METHODS: A cohort study was performed among 12,761 women, 40-79 years of age at baseline (1968-1973), who attended multiphasic health checkups that included mammography. The outcome measures included coronary heart disease (CHD), ischemic stroke, transient ischemic attack (TIA), hemorrhagic stroke, and heart failure, ascertained using discharge diagnosis codes and death records through December 31, 2000 (median follow-up, 24.8 years). RESULTS: Breast vascular calcification was present in 424 (3%) women. It was independently and positively associated with age, high parity, and diabetes and inversely associated with education level and current cigarette smoking. After adjustment for age, education level, race, cigarette smoking, alcohol use, body mass index (BMI), serum total cholesterol, hypertension, diabetes, parental history of myocardial infarction (MI), parity, and hormone replacement therapy (HRT), breast vascular calcification was associated with a 1.32-fold increased risk of CHD (95% confidence interval [CI] 1.08-1.60), a 1.41-fold increased risk of ischemic stroke (95% CI 1.11-1.78), and a 1.52-fold increased risk of heart failure (95% CI 1.18-1.98). CONCLUSIONS: Breast vascular calcification detected as part of a screening mammogram was an independent risk factor for multiple cardiovascular outcomes among women. The value of mammography in cardiovascular risk stratification deserves further investigation.