Mortality follow-up is now complete for 5 years in the 18 403 male civil servants aged 40-64 who were examined between 1967-69 in the Whitehall Study of British civil servants. During this period, 277 of them died of coronary heart-disease (C.H.D.); half of these deaths were in subjects in whom the findings at initial screening had suggested early myocardial ischaemia (angina or history of possible infarction according to standard questionnaire, or electrocardiographic evidence of ischaemia). The finding of suspect ischaemia had greater predictive power than the "primary" coronary risk factors, from which it was generally independent. At each level of the primary risk factors, the risk of death from C.H.D. was much greater in the presence of suspect ischaemia; and, with the possible exceptions of glucose tolerance and physical activity, the main risk factors still operated even at the stage of early ischaemia. These findings have implications for future studies of the effects of intervention.