Abstract  Although the prevalence of insomnia and the association of insomnia with menopause have been well reported, not much work has been conducted in population‐based research on insomnia and menopause in Korea. The purpose of the present report was to determine overall and different prevalence of insomnia by menopausal status, and the relationship between insomnia and menopause in a population‐based sample of middle‐aged Korean women. A total of 96.1% of 2497 randomly selected middle‐aged Korean women participated. Insomnia was defined as occurring three times a week or more in the previous month. Subjects were categorized into three groups: premenopaues, perimenopause, and postmenopause. The overall prevalence of insomnia in middle‐aged Korean women was 14.3%. The most common symptom of insomnia was difficulty maintaining sleep (9.7%), followed by difficulty initiating sleep (7.9%), and early morning awakening (7.5%). Multiple logistic regression analysis revealed that menopause was independently associated with insomnia after adjusting for confounding factors such as age, income, and depression. Perimenopause was significantly associated with a dramatic increase in the risk of insomnia, but there was no significant association for postmenopause. The major finding is that insomnia is significantly associated with the menopausal transition. The prevalence of insomnia increases significantly by the transition from premenopause to perimenopause, but not to postmenopause. A further prospective study is needed to investigate the influence of menopause on insomnia.