The prevalence of carotid atherosclerosis and of its risk factors was examined in 517 apparently healthy French women, aged 45-54 years. Early phases of carotid atherosclerosis were assessed by B-mode ultrasonography. An intimal-medial thickening was found in 30.4% of the women and atheromatous plaques in 8.7%. The prevalence rate of carotid atherosclerosis increased with age, smoking, and postmenopausal status. However, after adjustment for the effect of age, postmenopausal women did not have more atherosclerotic lesions than did premenopausal women. No significant associations were found between carotid atherosclerosis and triglyceride, apolipoprotein A-I, body mass index, blood glucose, fibrinogen, plasma viscosity, or hematocrit. The mean age-adjusted levels of total cholesterol, low density lipoprotein cholesterol, apolipoprotein B, and systolic and diastolic blood pressures significantly increased with the severity of carotid atherosclerosis, whereas high density lipoprotein cholesterol significantly decreased. Multiple regression analysis showed that age, smoking, high density lipoprotein cholesterol, low density lipoprotein cholesterol (or apolipoprotein B), and systolic (or diastolic) blood pressure were significantly and independently related to the severity of carotid atherosclerosis. In conclusion, the association of early carotid lesions with major cardiovascular risk factors suggests that carotid atherosclerosis may be used as a marker of the general atherosclerotic process.