Total antioxidant capacity (TAC) is a property of serum to overcome the oxidative stress to retain the cell structure healthy from the adverse effect of oxidative material. To investigate the Total antioxidant capacity and its association with insulin resistance in women with PCOS. The present study involved two groups, IR (n 59=) and NON-IR (n = 31) of PCOS patients.  TAC was measured using spectrophotometric assays. HOMA-IR method was used to assess the insulin resistance. Results were analyzed to compare and correlate IR with TAC. The median levels of serum insulin, HOMA-IR and TSH, were significantly higher among IR groups as compared to NON-IR groups (p‐value =.01, p‐value =.000, p‐value =.000) respectively. Moreover, the median of TAC was significantly lower among the IR group as compared to the NON-IR group (p‐value =.005). A significant negative correlation of TAC found with BMI (r=-.222 p < 0.036), WHR (r=-.246 p < 0.019), Insulin (r=-.388 p & p < 0.000) and HOMA-IR (r=-.403 p <.000). However, a significant positive correlation of TAC was found with LH (r=.337 p < 0.001). Insulin was found the major significant predictor of oxidative stress, as determined by a reduction in TAC levels, after adjusting for all study parameters (β=-2.861, P,0.001). Our study has highlighted the role of TAC and HOMA-IR in the pathogenesis of PCOS which supports the role of oxidative stress in the pathogenesis of IR which leads to PCOS. Therefore, these important biomarkers TAC and HOMA-IR help the clinicians in the treatment and management of the condition

Index Terms- Basal metabolic index, hyperglycemia, insulin resistance, Oxidative stress, Total antioxidant capacity