AIMS: To assess how trends in the incidence of coronary heart disease (CHD) and mortality rates among people with CHD have affected the prevalence of CHD in the UK. METHODS AND RESULTS: A time trend analysis using computerized general practice clinical records of people aged 35 years and over was performed. From 1996 to 2005, age-standardized incidence of CHD decreased by 2.2% in men and 2.3% in women per year (average percentage change). Age-standardized all-cause mortality among those with CHD decreased by 4.5% in men and 3.4% in women per year (average percentage change). Age-standardized prevalence increased by 1.3% in men and 1.7% in women per year (average percentage change). Although the decline in incidence had some impact on limiting the increase in prevalence, its effect was offset by the increase in prevalence occurring as a result of improved survival among people with CHD. CONCLUSION: The results suggest that increasing prevalence is largely due to decreasing mortality among people with CHD. Further increases in prevalence are likely even if the incidence of CHD continues to fall.