: Diabetic nephropathy is a major microvascular complication of diabetes mellitus and the most common cause of end stage renal disease worldwide. Plasma sialic acid is one of the markers that have been utilized as an acute-phase response . In diabetic nephropathy, there is a greater increase in sialic acid. We aimed in this study to shed light on the relationship between serum sialic acid and diabetic nephropathy in egyptian patients with type 2 DM. so studied 25 patients with diabetic nephropathy and 15 patients without diabetic nephropathy as well as 10 healthy volunteers as control. A questionnaire was done to every subject including baseline characteristics, examination and laboratory investigations. Serum sialic acid levels were found to be significantly increased in diabetic patients especially with nephropathy compared to controls. Conclusion: This prospective study showed that there is a strong association between elevated serum Sialic acid level with the presence of diabetic nephropathy in type 2 diabetic patients.