OBJECTIVES: We assessed the association of father's social class, recorded at the time of birth, with coronary heart disease and stroke in a British cohort of 11106 individuals born in the 1950s. METHODS: Survival analysis was used to relate social class at birth to the occurrence of either fatal or nonfatal coronary heart disease or stroke. RESULTS: Rates of coronary heart disease and stroke increased across the social class distribution from highest to lowest, and patterns of association were similar for the 2 outcomes. The gender-adjusted hazard ratio of experiencing either coronary heart disease or stroke comparing the manual and nonmanual social class categories was 1.52 (95% confidence interval [CI]=1.14, 2.02). This ratio fell to 1.41 (95% CI = 1.05, 1.88) after adjustment for indicators of intrauterine and childhood growth. Further adjustment for educational attainment reduced the ratio to 1.28 (95% CI=0.94, 1.75). CONCLUSIONS: We found that social class at birth was associated with risk of fatal and nonfatal cardiovascular disease among individuals born in the 1950s, a period of relative prosperity and after the introduction of the welfare state in Britain. This relation appeared to be mediated in part through educational attainment.