Diabetes mellitus (DM) is a universal public health problem and is associated with metabolic, cellular, and blood disorders. Haematological deviations have been reported in diabetes and play a vital role in diabetes-associated complications. Hemogram is one of the most common investigations, available in all hospitals where the NLR can be easily derived from the existing set of parameters measured in the blood sample. The NLR has been associated as a systemic inflammatory response marker in numerous diseases. Therefore, this study was carried out to derive correlation between NLR and DM and to analyze the association between the NLR and HbAlc values in patients of DM. In our study a total of 641 diagnosed cases of DM data were analysed and they were categorized as per the HbA1c value into Group A (n=414), Group B (n=102), Group C (n=125). Using a CBC, NLR was calculated and analyzed with IBM SPSS statistical grad pack 29.0 for Mean + SD, Chi-square, and Pearson correlation coefficient. There is a significant association amongst NLR and HbA1c values in diabetic patients (p < 0.001). The correlation analysis suggests a relationship amongst NLR and HbA1c levels, indicating that higher NLR values may be associated with higher HbA1c levels.