Is there evidence for a perimenopausal sleep disorder? We address this question in our presentation of the Study of Women's Health Across the Nation (SWAN) "sleep story," in which we summarize and discuss data addressing sleep quality, objective measures of sleep patterns, and sleep disorders that have been published to date by the SWAN and the ancillary SWAN Sleep Study. We describe what has been learned about sleep during the perimenopause. Analyses exploring racial/ethnic diversity and the role of hot flashes and mood disturbance in sleep-perimenopause associations are described. Implications for clinical practice are considered.