BackgroundSerum creatinine is an important laboratory marker of kidney function. It is used in the calculation of eGFR (estimated Glomerular Filtration Rate), which is used in the staging of Chronic Kidney Disease (CKD). In Sri Lanka, kinetic Jaffe and enzymatic methods are used to measure serum creatinine. ObjectivesThis study investigated the effect of interference by serum glucose on creatinine levels obtained by the kinetic Jaffe reaction compared to enzymatic method and thus their impact on staging of CKD. MethodsA cross-sectional analytical study was conducted in 83 patients with diabetes (serum glucose >180mg/dL). Serum creatinine was measured by kinetic Jaffe and enzymatic methods. Serum glucose values were also recorded in test samples. CKD-Epidemiology Collaboration (CKD-EPI) formula was used to calculate eGFR.