Vascular calcification is associated with mortality and cardiovascular events in patients with chronic kidney disease. AST-120, which adsorbs uremic toxins, is reported to reduce the risk of cardiovascular disease and death in chronic kidney disease patients. The aim of the current study was to investigate the association between abdominal aortic calcification and the use of AST-120 in predialysis chronic kidney disease patients. A retrospective analysis was conducted including 199 predialysis chronic kidney disease patients (stages 4 and 5) who underwent abdominal plain computed tomography in our institution between 2005 and 2010. Abdominal aortic calcification was assessed by aortic calcification index (ACI). Patients were divided into two groups based on whether or not AST-120 was administered for at least six months, and ACI was compared between the two groups. The aortic calcification index was significantly lower in patients taking AST-120 [12.2 (2.5–30.3) vs. 25.7 (13.4–45.3) %, P < 0.001]. According to multivariate linear regression analysis, the use of AST-120 was independently and significantly correlated with ACI after adjusting for confounding factors. The use of AST-120 was independently associated with less aortic calcification in predialysis chronic kidney disease patients.