Monitoring secular trends in mortality as well as morbidity from coronary heart disease (CHD) is important in order to relate favourable or unfavourable habits of daily living to the risk of disease, with a view toward effective preventive measures. A marked decline in CHD mortality has been observed in the United States during the past decade. Similar, but smaller, reductions have been recorded in a few other countries but the overall international tendency is toward unchanged or increasing mortality. There is a suggestion for countries with initially higher rates to register declines while the reverse tends to occur for low-mortality countries. The favourable trends in the United States can be linked to improvements in the style of life but parallel information in other countries is largely lacking. International, collaborative efforts to monitor CHD disease rates, living habits and risk factor distributions by country, region and social groups is a major need in the search for effective prevention programmes in the community.