Diabetes mellitus is a major health disease and may vary in clinical presentation and progression. Although Glucose Fasting and Post prandial levels give a measure of the current plasma glucose level, Glycated haemoglobin is the key analyte used to assess the glycemic control and risk of complications of patients with diabetes. Labile hemoglobin A1c is also known as pre-HbA1c or LA1c or pre-glycohemoglobin. It is an unstable form, (a Schiff base) formed during non-enzymatic glycation of hemoglobin. The concentration of labile fraction varies with acute change in plasma glucose level. Labile hemoglobin may potentially interfere in the estimation of HbA1c and cause a falsely low value and may even hamper or delay the prompt treatment required in diabetics. This calls for a detailed and careful study of chromatograms generated for each sample.