Aims: We aimed to assess the increased risk of death and severe vascular events in elderly individuals with subclinical or manifest peripheral arterial disease(PAD), evidenced by low ankle brachial index(ABI< 0.9) in primary care. Methods and results: In this monitored prospective observational study, 6880 representative unselected patients aged ≥65 years were followed up over 3 years by 344 primary care physicians. Main outcome measures were mortality or a combined endpoint of mortality and severe vascular events. In total, 20 127 patient-years were observed. In the group of PAD patients(n=1230), 134 patients died; in the group without PAD(n=5591), 237 patients died[multivariate hazard ratio(HR) 2.0; 95%confidence interval 1.6-2.5, P< 0.001]. Compared with an ABI≥1.1, the risk of death increased linearly in the lower ABI categories: ABI 0.7-0.89, HR 1.7(1.2-2.4, P< 0.001); ABI< 0.5, HR 3.6(2.4-5.4, P< 0.001). Conclusion: Patients with a low ABI(PAD), who can be readily identified in a primary care setting, have a substantially increased risk of death and severe vascular events. Patients with an ABI between 1.1 and 0.9 should be considered and followed up as borderline PAD cases. Particular attention should be paid to patients with PAD and previous vascular events, as their risk is markedly increased. Aims: We aimed to assess the increased risk of death and severe vascular events in elderly individuals with subclinical or manifest peripheral arterial disease (PAD), evidenced by low ankle brachial index (ABI <0.9) in primary care. Methods and results: In this monitored prospective observational study, 6880 representative unselected patients aged ≥65 years were followed up more than 3 years by 344 primary care physicians. Main outcome measures were mortality or a combined endpoint of mortality and severe vascular events. In total, 20 127 patient-years were In the group of PAD patients (n = 1230), 134 patients died; in the group without PAD (n = 5591), 237 patients died [multivariate hazard ratio (HR) 2.0; 95% confidence interval 1.6-2.5, P <0.001]. Compared with ABI ≥1.1, the risk of death increased linearly in the lower ABI categories: ABI 0.7-0.89, HR 1.7 (1.2-2.4, P <0.001); ABI <0.5, HR 3.6 , P <0.001). Conclusion: Patients with a low ABI (PAD), who can be readily identified in a primary care setting, have a substantially increased risk of death and severe vascular events. Patients with an ABI between 1.1 and 0.9 should be considered and followed up as borderline PAD cases. , as their risk is markedly increased.