Abstract: Hypothyroidism and Diabetes mellitus are among the most common endocrine disorders in India. Oxidative stress has been proposed to be one of the causative factors associated with insulin resistance. In our previous study, we reported the presence of oxidative stress in hypothyroidism. However, the link between oxidative stress and the status of insulin resistance in hypothyroidism has not been addressed yet especially among the Indians. We recruited sixty seven untreated hypothyroid patients consecutively from the out patient department and analyzed their homeostatic model assessment of insulin resistance (HOMA-IR) and oxidative stress parameters. Oxidative stress parameters and HOMA-IR were significantly higher compared to euthyroid controls. The severity of disease, body mass index and altered lipid profile, glycated hemoglobin and MDA levels were significantly associated with insulin resistance. However, only glycated hemoglobin and MDA levels were found to be independent predictors of HOMA-IR in these patients. Increased OS could be one of the mechanisms for mild insulin resistance as reported in our study in untreated hypothyroid patients.