OBJECTIVE– Study the importance of estimating Cystatin C over creatinine in early stage of kidney disease. Materials and Methods– A comparative study was done in different 55 patients presented with symptoms of kidney disease at different stages. Four groups of 55 patients were studied. Group–I of diabetic patients, Group–II of Chronic Kidney Disease (CKD), Group–III of Acute Kidney injury (AKD) and Group–IV of patients under dialysis conditions in the department of Biochemistry of YCM collage and hospital, Pimpri. A detailed history and clinical examination of creatinine from serum and Cystatin C level in different groups were compared. Result– Four groups of 55 patients were studied. Ceartinine and Cystatin c as biomarkers included in study seems to be increased from Group I to Group IV. e GFR calculated by Cystatin C test shows sharp decrease in value. However, compared to eGFR/Creatinine, value is higher in Control, Diabetic, Accute group and accurately low in Dialysis group. Therefore it clearly indicates that calculating e GFR using Cystatin C test is more significant and can acts as early stage biomarker. Conclusion– Cystatin C can be concluded as effective early stage biomarker over creatinine.