To assess contributions of childhood and adult social class to class gradients in women's health, the authors used gender-neutral household measures of class position in a retrospective cohort study of 630 women enrolled in Examination II of the Kaiser Permanente Women Twins Study (1989-1990, Oakland, CA). The age-adjusted odds of reporting fair or poor health was 2.3 times higher (95% confidence interval (CI)=1.2-4.1), using adult class measures, among women categorized as working class vs non-working class/professional. When stratified by childhood social class, however, the elevated risk of fair/poor health among adult working class compared to non-working class/professional women was evident only among those with a non-working class/professional childhood. Similarly, a working class tendency (based on adult class position) towards elevated levels of low density lipoprotein (LDL) cholesterol (odds ratio (OR)=1.5, 95% CI=0.9-2.7) and post-load glucose (OR=1.8, 95% CI=1.0-3.3) was apparent only among women who were non-working class in childhood. These results indicate that both childhood and adult class position influence class gradients in women's health in the United States.