Overweight and abdominal obesity increase mortality risk, although the risk may be mediated by traditional cardiac risk factors. The authors assessed the association of baseline measures, change in overall body weight and abdominal obesity (waist circumference), and weight and waist circumference cycling with total mortality among postmenopausal women with known heart disease. They used data from 2,739 US women who participated in the Heart and Estrogen/progestin Replacement Study between 1993 and 2001. Over 6.8 years of follow-up, 498 women died. In adjusted Cox models that included either baseline waist circumference or body mass index (BMI), each was associated with mortality. However, after further adjustment for diabetes, hypertension, and lipoproteins, these associations disappeared. In models including both waist circumference and BMI, larger waist circumference (hazard ratio=1.40 per standard deviation, 95% confidence interval: 1.16, 1.68) was associated with increased risk and higher BMI (hazard ratio=0.81 per standard deviation, 95% confidence interval: 0.67, 0.97) was associated with decreased risk of total mortality, independent of cardiac risk factors. Weight and waist circumference cycling were not associated with mortality. Results show that both BMI and waist circumference are associated with mortality among postmenopausal women with established heart disease, but waist circumference may be more important than BMI, and their effects may be largely mediated by other cardiac risk factors.