Kidney transplantation (KT) improved quality of life and longevity of CKD patients. Nevertheless, kidney function deteriorates overtime in a manner not different from CKD counterparts. Hypomagnesemia is prevalent in KT recipients secondary to immunosuppressive therapy. In addition to serum calcium, phosphate and elemental calcium intake, the relationship between low serum magnesium and vascular calcification (VC) has been observed in small studies in CKD. Whether low serum magnesium associates with VC in KT has never been elucidated. The present study compares vascular calcification between KT and CKD and its association with serum magnesium.