Background -Prediction of major cardiovascular and cerebrovascular events usi ng conventional risk factor models is limited. Noninvasive measures of subclinic al atherosclerosis such as the ankle brachial index(ABI) could improve risk pred iction and provide more focused primary prevention strategies. We wished to dete rmine the added value of a low ABI in the prediction of long-term risk of cardi ovascular and cerebrovascular events and death. Methods and Results -In 1988, 1 592 men and women 55 to 74 years of age were randomly selected from the age-sex registers of 11 general practices in Edinburgh, Scotland, and followed up over a period of 12 years for incident events. After adjustment for age and sex, an A BI ≤0.9 was predictive of an increased risk of fatal myocardial infarction(MI), cardiovascular death, all-cause death, combined fatal and nonfatal MI, and tot al cardiovascular events. After further adjustment for prevalent cardiovascular disease, diabetes, and conventional risk factors, a low ABI was independently pr edictive of the risk of fatal MI. Addition of the ABI significantly (P≤0.01) in creased the predictive value of the model for fatal MI compared with a model con taining risk factors alone. Comparison of areas under receiver operator characte ristic curves confirmed that a model including the ABI discriminated marginally better than one without. Conclusions -Addition of the ABI significantly improve d prediction of fatal MI over and above that of conventional risk factors. We re commend that the ABI be incorporated into routine cardiovascular screening and t hat the potential of its inclusion into cardiovascular scoring systems(with a vi ew to improving their accuracy) now be examined. Background -Prediction of major cardiovascular and cerebrovascular events usi ng conventional risk factor models is limited. Noninvasive measures of subclinic al atherosclerosis such as the ankle brachial index (ABI) could improve risk pred iction and provide more focused primary prevention strategies. We wished to dete rmine the added value of a low ABI in the prediction of long-term risk of cardi ovascular and cerebrovascular events and death. Methods and Results -In 1988, 1 592 men and women 55 to 74 years of age were randomly selected from the age- sex registers of 11 general practices in Edinburgh, Scotland, and followed up over a period of 12 years for incident events. After adjustment for age and sex, an A BI ≤0.9 was predictive of an increased risk of fatal myocardial infarction (MI), cardiovascular death, all-cause death, combined fatal and nonfatal MI, and tot al cardiovascular events. sk factors, a low ABI was independently pr edictive of the risk of fatal MI. Addition of the ABI significantly (P ≦ 0.01) in creased the predictive value of the model for fatal MI compared with a model con taining risk factors alone. Comparison of areas under receiver operator characte ristic curves confirmed that a model including the ABI discriminated marginally better than one without. Conclusions -Addition of the ABI significantly improve d prediction of fatal MI over and above that of conventional risk factors. We re commend that the ABI be incorporated into routine cardiovascular screening and t hat the potential of its inclusion into cardiovascular scoring systems (with a vi ew to improving their accuracy) now be examined.