Background: Chronic Kidney Disease (CKD) is becoming a major health concern worldwide. For many patients, CKD is associated with substantial morbidity and mortality. Osteopontin (OPN) is an extracellular matrix protein first identified in bone tissue and has pleiotropic functions due to its common expression in the main organs and apparatuses. It is a phosphorylated glycophosphoprotein composed of 314 amino acids, involved in biomineralization and remodeling. Objective: This research aimed to assess the serum level of osteopontin in patients with end-stage renal disease (ESRD) on regular haemodialysis and to correlate osteopontin level in patients with ESRD on hemodialysis with other biomarkers CKD-MBD. Patients & Methods: This Study was conducted on 160 participants that were divided into two groups. Control group included 80 healthy subjects of both sexes, and patients group that included 80 ESRD patients on regular hemodialysis of both sexes. All studied groups were subjected to osteopontin level by enzyme-linked immunosorbent assay (ELISA). Results: Serum osteopontin levels were higher in ESRD patients on regular dialysis than in healthy individuals, where it might have a higher predictive value for CKD development. Also, they were positively correlated with serum phosphorus, serum alkaline phosphatase and serum parathyroid hormone, which are parameters of chronic kidney disease-mineral and bone disorder. Conclusion: Osteopontin may be considered an early marker of chronic kidney disease.