Background: Concern about the potential risks associated with hormone replacement therapy (HRT) has left post-menopausal women and healthcare providers searching for safe and effective means for cardiovascular disease (CVD) risk factor reduction. Methods: The Woman On the Move through Activity and Nutrition study is a 5-year clinical trial (2002-2006) designed to test whether a lifestyle intervention will reduce measures of subclinical CVD. Participants were randomized at baseline to a health education or lifestyle change group. The impact of lifestyle intervention on CVD risk factors was examined in 240 women who were initially on HRT at baseline and either continued (n = 110) or discontinued (n = 130) by 18 months. Results: The lifestyle-change group significantly decreased weight, body mass index, waist circumference (all p<0.0001), total cholesterol (p=0.02), and LDL cholesterol (LDL-C) (p= 0.01), improved fat intake (p<0.0001), and increased leisure physical activity (p=0.005) when compared with the health education group. HRT discontinuation resulted in increased total cholesterol (p=0.04) and LDL-C (p=0.009). CVD risk factor changes were further explored by the HRT group, stratified by randomized group assignment. Within the health education arm, HRT discontinuers averaged over a 22-mg/dL increase in total cholesterol and LDL-C, while HRT continuers averaged less than 4 mg/dL (p=0.004 and 0.002, respectively). No such differences were noted in the lifestyle-change group (p=0.78 and 0.90, respectively). Conclusions: Lifestyle modification was effective for CVD risk factor reduction in post-menopausal women. HRT discontinuation resulted in increased total cholesterol and LDL-C, which were successfully attenuated by a lifestyle intervention incorporating weight loss, physical activity, and dietary modification. © 2007 American Journal of Preventive Medicine.