Arsenic (As) is an important environmental toxicant that can cause cancer and cardiovascular disease, but the relationship between As exposure and renal dysfunction is not clear. The aim of this study is to examine the association between As exposure and renal dysfunction in a community-based population in central Taiwan. One thousand and forty-three subjects were recruited between 2002 and 2005. The risk for type 2 diabetes was increased by 2-fold (p < 0.05) in subjects with total urinary As (U-As) > 75 μg g-1 creatinine as compared with subjects whose U-As was ?35 μg g-1 creatinine after the adjustment for potential confounders. The adjusted odds ratio for an abnormal β2 microglobulin (B2MG > 0.154 mg L-1) was significantly higher in subjects with U-As > 35 μg g-1 creatinine as compared with the reference group adjusted for age, sex, living area, cigarette smoking, diabetes, and hypertension. The risk for abnormal B2MG and estimated glomerular filtration rate (eGFR < 90 mL min-1 (1.73 m2)-1) was both increased around 2-fold (p < 0.05) in subjects with U-As > 75 μg g-1 creatinine as compared with those with U-As ? 35 μg g-1 creatinine adjusted for all the risk factors plus lead (Pb), cadmium and nickel. The prevalence of abnormal B2MG was 4.82 times higher in subjects with both over the median levels of U-As (85.1 μg L-1) and urinary Pb (18.9 μg L-1) as compared to both lower than the median (p < 0.001). These results indicate that U-As might relate to renal dysfunction even other important risk factors were taken into account. Follow-up studies for causal inference are warranted.