OBJECTIVE: To examine whether retinal vascular calibre independently predicts risk of coronary heart disease (CHD) -related death. METHODS: In a population-based cohort study of 3654 Australians aged > or = 49 years, retinal arteriolar and venular calibres were measured from baseline retinal photographs and the arteriole to venule ratio (AVR) was calculated. CHD-related death was confirmed from the Australian National Death Index. RESULTS: Over nine years, 78 women (4.1%) and 114 men (7.8%) had incident CHD-related deaths. In people aged 49-75 years, wider venules were associated with CHD death, with relative risk (RR) 1.8 (95% confidence interval (CI) 1.1 to 2.7) and RR 2.0 (95% CI 1.1 to 3.6) per standard deviation (SD) increase in venular calibre for men and women, respectively, after adjustment for traditional risk factors. Additionally, in women aged 49-75 years, smaller AVR and narrower arterioles were associated with CHD death (RR 1.5, 95% CI 1.1 to 2.2, and RR 1.9, 95% CI 1.0 to 3.5 per SD decrease in AVR and arteriolar calibre, respectively, after adjustment). These associations were not observed in people aged > 75 years. CONCLUSIONS: These findings suggest that microvascular disease processes may have a role in CHD development in middle-aged people, particularly in women. Retinal photography may be useful in cardiovascular risk prediction.