OBJECTIVE Changes in cardiovascular risk factors with menopausal status are difficult to study, owing to the high correlation of menopausal status with age. Therefore we examined cardiovascular risk factors in a meticulously selected population in which the contrast in oestrogen status between pre- and postmenopausal women of the same age was maximized. METHODS Risk factors were compared in 93 premenopausal and 93 postmenopausal women who were matched on age (range 43-55 years). METHODS The women were selected from respondents to a mailed questionnaire about the menopause, which was sent to all women aged 40-60 years in the Dutch town of Zoetermeer (n = 12 675; response 54%). METHODS Postmenopausal women who were at least 3 years after menopause or whose menses had stopped naturally before age 48 were age-matched with premenopausal women with regular menses and without menopausal complaints. RESULTS Compared to premenopausal women, postmenopausal women had significantly increased levels of total cholesterol (10.0%, 95% confidence interval 5.1-14.0), low density lipoprotein (LDL) cholesterol (14.0%, 6.9-19.9), and apolipoprotein B (8.2%, 0.6-15.5). The difference was present within 3 years after onset of menopause and did not show a trend towards an increase with the number of postmenopausal years. No differences were found in high density lipoprotein (HDL) cholesterol, triglycerides, apolipoprotein A1, blood glucose, insulin, body mass index, waist-to-hip ratio, and systolic and diastolic blood pressure. CONCLUSIONS The results of this study add to the evidence that total cholesterol, LDL cholesterol and apolipoprotein B are the primary cardiovascular risk factors affected by menopause.