A major limitation of past work on the social patterning of atherosclerosis has been the reliance on measures of neighborhood or individual-level socioeconomic position (SEP) assessed at a single point in time in adulthood. Risk of chronic disease is thought to accumulate throughout the life-course, so the use of a measure for a single point in time may result in inaccurate estimates of the social patterning of subclinical disease. Using data from the US Multi-Ethnic Study of Atherosclerosis (MESA), we examined the relation between childhood SEP [CSEP] (father or caretaker's education), adulthood SEP [ASEP] (a summary score of income, education, and wealth), and 20-year average exposure to neighborhood poverty [NSEP] (residential addresses geocoded and linked to census data) and the prevalence of subclinical atherosclerosis, as assessed by common carotid intimal-medial thickness (IMT) in mid to late adulthood. Participants were 45-84 years of age at baseline and were sampled from six study sites in the United States. After adjustment for age, CSEP and ASEP were both inversely and independently associated with IMT in men. All three indicators CSEP, ASEP, and NSEP were inversely and independently associated with IMT in women. Associations were somewhat reduced after adjustment for cardiovascular risk factors, suggesting that these factors may play a mediating role. There was evidence of heterogeneity in effects of NSEP by gender, and in the effects of ASEP and NSEP by race/ethnicity. Our results contribute to the growing body of work that shows that SEP at multiple points in the life-course, and at the individual and neighborhood level, contributes to the development of atherosclerosis.