Panic attacks are known to be more common in women than in men, but the prevalence and correlates of panic in the postmenopausal period have not been well defined. Cross-sectional survey of 3369 community-dwelling postmenopausal women enrolled between December 1, 1997, and November 30, 2000, in the Myocardial Ischemia and Migraine Study, a 10-center ancillary study of the 40-center Women's Health Initiative. Participants, aged 50 to 79 years and predominantly white (73%), completed questionnaires about the occurrence of panic attacks in the previous 6 months and about migraine headaches and underwent 24-hour ambulatory electrocardiographic monitoring. The 6-month prevalences of full-blown and limited-symptom panic attacks were calculated, and their associations with other sociodemographic and clinical variables were examined in multivariate analyses. One of the panic attack types was reported by 17.9% (95% confidence interval, 16.6%-19.2%) of women (full-blown attacks, 9.8%; limited-symptom attacks, 8.1%). Adjusting for age and race or ethnicity, full-blown panic attacks were more common in women with a history of migraine, emphysema, cardiovascular disease, chest pain during ambulatory electrocardiography, and symptoms of depression. Full-blown panic attacks were associated in a dose-response manner with negative life events during the past year. Panic attacks were associated with functional impairment even after adjusting for comorbid medical conditions and depression. There was no significant association with self-reported use of hormone replacement therapy. Panic attacks may be relatively common among postmenopausal women and seem to be associated with stressful life events, medical comorbidity, and functional impairment.