INTRODUCTION: Middle-aged women are often faced with the dilemma of whether to use hormone therapy or not. Until recently, advertisements, as well as, very often, the scientific literature, advocated the use of hormone therapy. The aim of this study was to determine women's use of hormone therapy and its correlation with age, self-rated health status and lifestyle factors. MATERIALS AND METHODS: An anonymous postal questionnaire was sent to 5,300 women over 44 years of age. The public health insurance office in Roskilde County picked 100 women at random for each of the 53 general practitioners who entered the survey in 1998. 72% of the women answered the questionnaire. The data set was statistically analysed using multiple linear logistic regression, taking account of the fact that the data had been obtained through general practitioners. RESULTS: 35% (95% CI 32-38) of the women 50-55 years of age were currently using or had formerly used hormone therapy. As many as 51% (95% CI 46-56) of the women 60-64 years of age were currently using or had formerly used hormone therapy. More than 50% of the women who were using hormone therapy had done so for more than 10 years. The group of women 45-59 years of age with the worst self-rated health status had odds of 5.1 (95% CI 3.0-8.6) of current or former use of hormone therapy as compared with the women with the highest self-rated health status. The odds of current use of hormone therapy were comparable at 2.7 (95% CI 1.5-4.7) for the women with the lowest self-rated health status as compared with the women with the highest self-rated health status. There was a positive correlation between the use of hormone therapy and physical exercise, tobacco use, former use of oral contraceptives and examination of cholesterol level. DISCUSSION: The percentage of women over 44 years of age who currently use or have formerly used hormone therapy in our study is comparable with the results of Danish surveys since 1983. Women 45-59 years of age who use hormone therapy do not have the same high level of self-rated health as that of women aged 45-59 years who have not used hormone therapy.