This study was performed on 53 patients from Kasr El Aini University hospital, Internal Medicine and Nephrology Department. The patients were divided into 3 groups:-Group 1:-17 patients with acute renal failure, Group 2:- 27 patients non-diabetic with CRF on regular hemodialysis for at least 6 months, Group 3:- 9 controls with normal renal functions. Each patient was subjected to full history taking, full clinical examination and laboratory investigations including:- (S. creatinine, Bl. Urea, S. calcium, S. phosphorus, P.T.H, S. cholesterol, S. triglyceride, S. albumin , and F.G.F.23{fibroblast growth factor 23}) and non contrast CT abdomen and A.C.I. was measured. FGF23 levels showed significant difference between the studied groups as in ARF=2498.8±1669.1, CRF=6030±4141.5 and controls=95.8±52.3 with significant P-value=0.0001. Also ACI showed significant difference between the studied groups as in ARF=4.1±9.0, CRF=15.5±10.2 and controls=3.7±3.8 with significant P-value=0.001. In multiple regression analysis showed ACI correlated with FGF 23 in ARF with significant P-value=0.014 and CRF with significant P-value=0.004. We concluded that there is strong positive relationship between FGF23 and ACI. This positive correlation may open the gate for routine estimation of this agent as a surrogate marker of arterial calcification.