Cardiovascular disease is the leading killer of women in developed countries. Menopause, stress, and lack of social support may contribute to the increased risk of heart disease morbidity and mortality in women. This study examined the effects of psychological stress and social support on autonomic nervous system control of the heart in 18 pre- and 34 postmenopausal women. Autonomic activity, as indexed by high-frequency heart rate variability and pre-ejection period, was assessed at rest and during a public speech task. Social support was determined using the Berkman Social Support Inventory. Postmenopausal women had higher heart rate (F = 4.4, p pound.04) and less parasympathetic activity (F = 11.9, p pound.001) compared with premenopausal women at rest. In response to stress, sympathetic nervous system activity increased in postmemopausal women (F = 6.1, p pound.02); however, this effect was no longer significant when age was used as a covariate in the analysis. Social support did not significantly affect measures of autonomic activity in either the pre- or postmenopausal women. Postmenopausal women have greater sympathetic and less parasympathetic activity than premenopausal women, which may account for their increased risk of coronary artery disease.