ABSTRACT: Childhood socioeconomic status (SES) is related to risk for cardiovascular disease in adulthood, perhaps, in part, due to associations with inflammatory and hemostasis processes. We tested the hypotheses that childhood SES is related to C-reactive protein (CRP), fibrinogen, factor VIIc, and plasminogen activator inhibitor-1 (PAI-1) in midlife women and that the associations are mediated by adult SES and/or adult body mass index (BMI).Using data from the prospective Study of Women's Health Across the Nation, we classified 1067 black and white women into 3 multidimensional childhood SES groups based on latent class analysis. Biological measures were assessed across 7 years along with covariates and mediators and analyzed by mixed regression models, followed by tests for mediation.Compared with women raised in high SES families, those from the lowest SES families had higher levels of CRP (b [standard error] = 0.37 [0.11]), PAI-1 (b = 0.23 [0.07]) factor VIIc (b = 0.05 [0.02]), and fibrinogen (b = 11.06 [4.89]), after adjustment for ethnicity, site, age, ratings of health between ages 11 and 18 years, visit, smoking status, menopausal status, stroke or heart attack, medications, and hormone use. Introduction of adult SES and BMI into the models reduced the childhood SES associations to nonsignificance for all four measures. Indirect mediation was apparent for adult education and BMI for CRP, and BMI for PAI-1.Women raised in lower SES families had elevated markers of inflammation and hemostasis, in part, due to elevated BMI and education in adulthood.