Background Few national estimates of the prevalence of coronary heart disease in the United Stares are available. Methods By using data from the Third National Health and Nutrition Examination Survey (1988 to 1994), we estimated prevalence of angina pectoris by questionnaire, self-reported myocardial infarction, and electrocardiographically (EGG)-defined myocardial infarction. Results Among participants aged greater than or equal to 40 years who attended the medical examination, the age-adjusted prevalence of angina pectoris, self-reported myocardial infarction, and EGG-defined myocardial infarction were 5.8% of 9255; 6.7% of 9250, and 3.0% of 8206 participants, respectively. Among participants aged greater than or equal to 65 years compared with those aged 40 to 64 years, the prevalence of a self-reported myocardial infarction was more than 3 times higher and that of EGG-defined myocardial infarction more than 4 times higher. The prevalences of self-reported myocardial infarction and EGG-defined myocardial infarction, but not angina pectoris, were higher among men than women. Among women, prevalence of angina pectoris and self-reported myocardial infarction were highest among blacks; among men, these coronary heart diseases were somewhat higher among whites. Prevalence of EGG-defined myocardial infarction were similar for all 3 race or ethnicity groups in either sex. The age-adjusted prevalence of coronary heart disease defined by the presence of any of these conditions was 13.9% among men and 10.1% among women. Conclusions Although the management of coronary heart disease has improved during the past 2 decades, it remains an important prevalent disease burden among adults.