The Study of Women’s Health Across the Nation at Pittsburgh will soon be launching another new study in collaboration with SWAN sites in University of California Davis and Kaiser Permanente, University of Michigan, and Rush Presbyterian-St. Luke’s Medical Center, Chicago, IL. This study will characterize the relationship between menopausal characteristic and sleep in a sample of 430 women: 200 Caucasian, 150 African-American, and 80 Chinese. Although sleep disruptions, insomnia, and the incidence of sleep disordered breathing increase in mid-life women, little is known about the relationship between menopause and sleep. The impact of vasomotor symptoms and hormone replacement therapy on sleep suggests that the sleep-menopause relationship is not merely a function of age. A greater understanding of the causes of sleep disturbances in mid-life women is important, given the impact of sleep on mental and physical health. Sleep disturbances are associated with a host of negative health outcomes including losses in productivity and quality of life, psychiatric morbidity, immunosuppression, and increased vulnerability to illness and disease. Study aims are to increase our understanding of the relationships among menopausal characteristics and sleep disturbances, evaluate the influence of relevant psychobiological factors on the sleep-menopause relationship, and establish baseline data for a future longitudinal study.