In the Whitehall Study, which followed 17,139 male civil servants over 33 years, the association between tall stature and coronary heart disease (CHD) mortality differed between employment grades. In men without CHD at study entry, the hazard ratio per 15-cm increase in height was 0.77 (95% confidence interval [CI]=0.69, 0.85; P<0.001) for the highest grades, but 0.84 (95% CI=0.69, 1.03; P=.10) for middle and 0.95 (95% CI=0.75, 1.20; P=.65) for low grades, suggesting that childhood and adult social conditions may interact in their influence on coronary risk.