We investigated the impact of family history of myocardial infarction on 12-year coronary heart disease mortality. Men and women with a family history had an increased risk for coronary heart disease death, irrespective of other risk factors (RR = 1.58; 95% CI = 1.17-2.13 and RR = 2.12; 95% CI = 1.11-4.05, respectively). Women with a family history seemed to be more susceptible to the detrimental effects of smoking; not to the effects of other risk factors. We found no effect modification by family history in men.