Aim: Although our recent cross-sectional study demonstrated that the CHADS2 score is associated with an ankle-brachial index of 0.9 in patients without atrial fibrillation (AF), the true cause-effect relationship between these parameters remains to be evaluated. Hence, the aim of this study was to investigate whether the CHADS2 score is a useful predictor of new-onset PAOD in non-AF patients. (score 5) and 291 (score 6) patients were studied and followed for the onset of PAOD. We further divided the study patients into four groups: group 1 (score 0), group 2 (score 1-2), group 3 (score 3-4) and group 4 (score 5-6). Results: During the follow-up period of 9.83 0.01 years, 24,775 (3.4%) patients experienced newonset PAOD. The overall incidence of PAOD was 0.6 per 1,000 patient-years. The rate of PAOD increased from 1.8% (group 1) to 18.7% (group 4) (p 0.001). According to a multivariate analysis, groups 2-4 were significantly associated with new-onset PAOD (all p 0.001). In addition, the hazard ratio of each two-point increment in the CHADS2 score for predicting PAOD was 2.51 (p 0.001). Conclusions: The CHADS2 score is a useful predictor of new-onset PAOD in non-AF patients. J Atheroscler Thromb, 2015; 22: 490-498.