Blurb Diabetes Mellitus is one of the leading non-communicable diseases all over the world including Bangladesh. OGTT still is regarded as gold standard in diagnosis of blood glucose abnormality. Although measurement of HbA1C is considering as an alternate tool to identify risk group. The present study was undertaken to evaluate the role of measurement of HbA1C in the diagnosis of diabetes and pre-diabetes in middle-aged Bangladeshi subjects. A total 177 subjects were selected for the purpose and classified into healthy control (n=62) pre-diabetes (n= 69) and diabetes (n=46) groups based on the values of OGTT. The optimal cut-off value of HbA1C related to pre-diabetes diagnosed by OGTT was 5.6%, which showed the sensitivity 47.8%, specificity 74.2%, positive predictive value 67.3% and negative predictive value 58.5%. Variants of hemoglobin especially Hemoglobin E (HbE) is prevalent in South East Asia including Bangladesh. The presence of genetic variants of Hb can profoundly affect the accuracy of HbA1c measurement.So measurement of HbA1C is not an alternate diagnostic tool of OGTT to identify people at risk for diabetes and pre-diabetes in middle-aged Bangladeshi population.