BACKGROUND Although coronary heart disease mortality has been decreasing, little is known about trends in morbidity from coronary heart disease. We evaluated trends in nonfatal coronary heart disease in the United States during 1980 through 1989. METHODS We analyzed data from the National Health Interview Survey, an ongoing survey of representative samples of the civilian, noninstitutionalized population of the United States. Survey respondents were determined to have coronary heart disease if they reported ever having a myocardial infarction or heart attack, angina pectoris, or coronary heart disease. Incidence was defined as initial onset of a coronary heart disease condition during the year preceding the interview date. RESULTS About 6 million people were estimated to be living with coronary heart disease. The age-standardized prevalence was relatively constant at about 25 per 1000. Among white men, however, prevalence increased significantly over the 10-year period. Among 75- to 84-year-old men, prevalence increased from 100 per 1000 in 1980 to 179 per 1000 in 1989. Among men and women 45 to 54 years old, prevalence decreased. Overall, the incidence rate of nonfatal coronary heart disease was relatively flat (at about 3 per 1000 per year after 1983). Among white women, the incidence rate increased from 1.4 to 2.8 per 1000, and by the end of the decade it nearly equaled the incidence rate among white men. CONCLUSIONS Overall, the burden of nonfatal coronary heart disease remained fairly constant during the 1980s. The trends, however, were not uniform in all population groups. The apparent increasing incidence among women deserves continued monitoring. An encouraging trend is the decreasing prevalence in the younger age groups.