The objective of our study was to examine age-specific mortality rates from coronary heart disease (CHD), particularly those among younger adults. Trends for obesity, diabetes, blood pressure, and metabolic syndrome among young adults raise concerns about the mortality rates from CHD in this group. We used mortality data from 1980 to 2002 to calculate age-specific mortality rates from CHD for U.S. adults age > or =35 years. Overall, the age-adjusted mortality rate decreased by 52% in men and 49% in women. Among women age 35 to 54 years, the estimated annual percentage change (EAPC) in mortality was -5.4% (95% confidence interval [CI] -5.8 to -4.9) from 1980 until 1989, -1.2% (95% CI -1.6 to -0.8) from 1989 until 2000, and 1.5% (95% CI -3.4 to 6.6) from 2000 until 2002. Among men age 35 to 54 years, the EAPC in mortality was -6.2% (95% CI -6.4 to -5.9) from 1980 until 1989, -2.3% (95% CI -2.6 to -2.1) from 1989 until 2000, and -0.5% (95% CI -3.7 to 2.9) from 2000 until 2002. Among women and men age > or =55 years, the estimated annual percentage decrease in mortality from CHD accelerated in more recent years compared with earlier periods. The mortality rates for CHD among younger adults may serve as a sentinel event. Unfavorable trends in several risk factors for CHD provide a likely explanation for the observed mortality rates.