Background: It was believed that nutritional iodine deficiency, which causes developmental issues and endemic goitre, was restricted to the Himalayan and Sub-Himalayan regions. In the 1980s, both isolated studies by individual investigators (9, 10) and a multi-centric national study by the Indian council of Medical research demonstrated countrywide prevalence. Aims and Objectives: To investigate the association between HbA1c and serum TSH levels. Materials & Methods: Santosh Medical College and hospital, Ghaziabad, Department of Medicine, on patients who will be visiting the Santosh Hospital Ghaziabad, Department of Medicine Outpatient Department. Due to the fact that this hospital serves all parts of society, the sample obtained from this institution accurately represents the population of India from 1 June 2019 to 31 May 2020. The trial will include 500 participants with type-2 diabetes mellitus, regardless of age or gender, who randomly appear at the Santosh hospital. Results: HbA1c and TSH have a correlation of.345, which is a weakly positive connection. With a P value of.001, the correlation between two variables is statistically significant. As the TSH value increases, the HbA1c value likewise increases, albeit the link is modest. Conclusion: Ten percent of the whole study group, or 54 individuals, are between the ages of 50 and 59, which has the highest frequency of thyroid problems among type 2 diabetes patients. A total of 73 participants, or 14.6% of the entire study group, had diabetes for between 1 and 5 years. With an overall incidence of 34%, the current study indicates a definite female preponderance. On the basis of the findings of this study, it is recommended that persons with type 2 diabetes receive thyroid disease screening. However, additional information is required, which can be gathered from larger investigations