A population study of women in Goteborg, Sweden, was carried out in 1968-1969. Altogether 1462 women participated (participation rate 90.1%). Five age strata were studied: 38, 46, 50, 54 and 60 (women born in 1930, 1922, 1918, 1914 and 1908, respectively). The same women were restudied in 1974-1975. At this time 1302 women participated, corresponding to 89.1% of those studied in 1968-1969 and 80.3% of those initially sampled. The vast majority of the women had a natural menopause. The median age at menopause was about 50. The criteria for definition of menopause are discussed. No support was found for the theory of increased menopausal age with time. Estrogen therapy of postmenopausal women was much more common in 1974-1975 than in 1968-1969.