BACKGROUND There has been a major decline in mortality from coronary heart disease (CHD) in Australia from about 1967 through to 1989, occurring across all age groups simultaneously. We have analysed data up until 1992 to examine for trends within age cohorts. METHODS Death registrations for acute myocardial infarction and CHD were used to construct male and female 5-year age- and cohort-specific mortality rates starting at 1900-1904 for cohorts and 25-29 years for age. Trends within age group and within cohort were compared across time. RESULTS Across all female and most male birth cohorts there was a decrease in CHD mortality across the time period. In the youngest male cohorts there was a significant flattening in the rate of decline in the most recent periods. Comparison of age-specific mortality across cohorts showed the mortality at any period to be lower in the most recent cohort. CONCLUSIONS This analysis demonstrates a continuing decline in mortality from CHD among females of all ages in Australia although the rate of decline appears to have slowed or even ceased in younger males.