There is increasing evidence from epidemiological studies that exogenous estrogen (hormone replacement therapy) protects against the elevated risk of cardiovascular disease in women after the menopause. However, it is still uncertain whether the postmenopausal decrease in endogenous estrogen in itself contributes significantly to this increase in risk. Most of the studies that have provided evidence linking cardiovascular disease with menopause have involved North American women, who may differ significantly from Europeans in terms of lifestyle and diet. ICARUS (Italian Climacteric Research Group Study) is an observational study that involves Italian Menopause Clinics, with the objective of collecting observational data on menopause and its management. The results of a cross-sectional analysis of 9309 women, free from any hormonal treatment and enrolled up to March 1997, are reported here. Data show that the menopause has a marked effect on the circulating levels of lipids and lipoproteins. From pre- to post-menopause there are significant increases in total cholesterol (6.9% before and 4.4% after adjustment for covariates including chronological age, educational level, center, BMI, smoking habits, hypertension and diabetes, previous contraceptive use, and time since menopause), LDL (7.5% before, 4.0% after), and triglycerides (9.0% before, 3.2% (ns) after). However, there is no significant change in HDL. Among postmenopausal women, no effect on lipid profile of time since menopause was observed.