This study examined the role of several personal characteristics in the association between low job control and coronary heart disease among male and female British civil servants. The logistic regression analyses were based on a prospective cohort study (Whitehall II), comprising 6,895 men and 3,413 women, age 35-55 years. Men and women with low job control at baseline had 1.5 to 1.8 higher risks of new heart disease during the 5.3-year follow-up. Psychological attributes, such as hostility, negative affectivity, minor psychiatric disorder, and coping, affected this association very little. The personal characteristics were not confounders, intermediate factors, or effect modifiers. Hence, increasing job control could, in principle, lower risks of heart disease for all employees.