OBJECTIVE: Albuminuria is recognized as a marker of vascular dysfunction. Brachial-ankle pulse wave velocity (baPWV) reflects the stiffness of central and peripheral muscular arteries. Limited information is available for the association between albuminuria and arterial stiffness in Chinese. We aimed to assess the association between albuminuria and arterial stiffness in a middle-aged population-based study. METHODS: A total of 2180 subjects aged 40 years and over were recruited in 2004 in Taiwan. Albuminuria was defined as urinary albumin-to-creatinine ratio (ACR)>or=30 mg/g creatinine. BaPWV was divided by quartile. Multiple logistic and linear regression analyses were used to evaluate the relationship between baPWV and albuminuria. RESULTS: After adjusting for age, body mass index, mean arterial pressure, fasting glucose, triglycerides, total cholesterol, chronic kidney disease, smoking, alcohol drinking, and physical activity status, multiple logistic regression analyses revealed baPWV groups were significantly associated with albuminuria. Compared to the lowest baPWV quartile, the adjusted odds ratio of having albuminuria for baPWV quartile II, III, and IV were 1.12(0.63-2.02), 2.04(1.15-3.60), and 2.45(1.29-4.65). The significant increase in odds ratios for albuminuria in progressive baPWV quartiles reveals a dose-response effect (p<0.001). Among diabetic, hypertensive, and macroalbuminuria subjects, these relationships were stronger than in subjects without diabetes, hypertension, and microalbuminuria. Moreover, multiple linear regression analyses showed that baPWV was significantly associated with urinary ACR after adjusting for potential confounders. CONCLUSION: Albuminuria was strongly related to arterial stiffness among Chinese middle-aged adults. These relationships were enhanced in subjects with hypertension, diabetes, or macroalbuminuria.