Beginning in the 1920s, death rates from coronary heart disease in the United States rose in an unyielding fashion reaching epidemic proportions by the mid-1960s. Since that time, mortality attributed to coronary heart disease has leveled off and then turned markedly downwards. In the ten-year period between 1968 and 1978 there was a greater than 25 percent decline in the overall age-adjusted death rate from coronary heart disease, a phenomenon observed in both sexes, all age groups and in the three major race/ethnic groups. While this significant and encouraging decline appeared real and not due to artifactual changes in death certification practices, the causes of this decrease remain obscure and coronary heart disease continues as a major cause of death and disability in the United States. Internationally, inconsistent trends in mortality rates attributed to coronary heart disease have occurred. These rates declined from the early 1960s for Australia, Canada, France, Japan, Switzerland and Italy while mortality rates from coronary heart disease continued to increase from this period until the late 1970s for England and Wales, Ireland, Finland, Norway, New Zealand and Israel.