Intima-media thickness of the common carotid arteries is a marker of atherosclerosis and has been shown to be associated with prevalent and incident coronary heart disease and with coronary heart disease risk factors. The authors examined the association of baseline risk factors or change in risk factors with change in intima-media thickness over follow-up (1987-1998) in the Atherosclerosis Risk in Communities (ARIC) population-based cohort (baseline: age 45-64 years, n = 15,792). Subjects were members of households sampled in four areas of the United States. Either not adjusting for baseline intima-media thickness or doing so with correction for its measurement error resulted in statistically significant associations of change in intima-media thickness with baseline diabetes, current smoking, high density lipoprotein cholesterol, pulse pressure, white blood cell count, and fibrinogen. The associations were of a similar order of magnitude as anticipated from the authors' cross-sectional findings. Statistically significant associations were found between change in intima-media thickness and change in low density lipoprotein cholesterol and triglycerides and with onset of diabetes and hypertension. In summary, established risk factors for coronary heart disease are associated with the rate of change of subclinical atherosclerosis.