AbstractIn epidemiologic studies, high arsenic exposure has been associated with adverse kidney disease outcomes. We performed a systematic review of the epidemiologic evidence of the association between arsenic and various kidney disease outcomes. The search period was January 1966 through Jan-uary 2014. Twenty-five papers (comprising 24 studies) meet-ing the search criteria were identified and included in this review. In most studies, arsenic exposure was assessed by measurement of urine concentrations or with an ecological indicator. There was a generally positive association between arsenic and albuminuria and proteinuria outcomes. There was mixed evidence of an association between arsenic exposure and chronic kidney disease (CKD), β-2-microglobulin (β2MG), and N-acetyl-β-D-glucosaminidase (NAG) out-comes. There was evidence of a positive association between arsenic exposure and kidney disease mortality. Assessment of a small number of studies with three or more categories showed a clear dose-response association between arsenic and prevalent albuminuria and proteinuria, but not with CKD outcomes. Eight studies lacked adjustment for possible confounders, and two had small study populations. The eval-uation of the causality of the association between arsenic exposure and kidney disease outcomes is limited by the small number of studies, lack of study quality, and limited prospec-tive evidence. Because of the high prevalence of arsenic exposure worldwide, there is a need for additional well-designed epidemiologic and mechanistic studies of arsenic and kidney disease outcomes. Keywords Arsenic.Kidney disease.Kidney.Proteinuria. Systematic review