Background: Glomerular filtration rate (GFR) is important for assessing the functional capacity of the kidney. Reduction in GFR ≤ 60ml/min/1.73m2 or presence of kidney damage defines Chronic Kidney Disease (CKD). Progression of kidney disease without medical intervention is associated with increase morbidity and mortality. Risk factors like uncontrolled diabetes mellitus, hypertension and obesity have been shown to be associated with CKD. These factors act synergistically to cause progressive decline in GFR and renal function. Traditionally, GFR is estimated based on serum Creatinine concentration using Creatinine based formula such as Cockroft-Gault but this is not sensitive for early prediction of CKD. However, there are reports that serum Cystatin C concentration is a better indicator of GFR especially in those patients at risk of developing chronic kidney disease. Aim and Objectives: This study examined the correlation between Creatinine and Cystatin C based estimations of glomerular filtration rate (GFR) among patients at risk of developing CKD. Methodology: Serum samples were assayed for estimation of Creatinine and Cystatin C in 172 subjects divided into four subgroups and 64 subjects serving as controls. Two results for estimated glomerular filtration rate (eGFR) were generated using serum creatinine (Cr) and cystatin C. Cockroft-Gault formula was used to calculate eGFR-Cr and simple cystatin C formula was used to calculate eGFR-Cystatin. The results of eGFR were correlated and compared between the subjects and controls. Receiver operator curves were constructed and analysed to determine the diagnostic accuracy between simple Cystatin C formula and Cockroft-Gault formula.