Borderline ankle-brachial index is increasingly recognised as a marker of cardiovascular risk. We evaluated the impact of borderline ankle-brachial index in 12,772 Chinese type 2 diabetes patients from the Joint Asia Diabetes Evaluation Program between 2007 and 2012. Cardiovascular risk factors, complications and health-related quality of life were compared between patients with normal ankle-brachial index (1.0-1.4), borderline ankle-brachial index (0.90-0.99) and peripheral arterial disease (ankle-brachial index < 0.9). The prevalence of peripheral arterial disease and borderline ankle-brachial index was 4.6% and 9.6%, respectively. Borderline ankle-brachial index patients were older, more likely to be smokers and hypertensive, had longer duration of diabetes, poorer kidney function and poorer health-related quality of life than patients with normal ankle-brachial index. After adjustment for traditional cardiovascular risk factors, borderline ankle-brachial index was an independent predictor of diabetes-related micro-and macrovascular complications including retinopathy (odd ratios: 1.19 (95% confidence interval: 1.04-1.37)), macroalbuminuria (1.31 (1.10-1.56)), chronic kidney disease (1.22 (1.00-1.50)) and stroke (1.31 (1.05-1.64)). These findings suggest that patients with diabetes and borderline ankle-brachial index are at increased cardiovascular risk and may benefit from more intensive management.