Objective: We aimed to evaluate whether triglyceride and glucose (TyG) indices are useful in identifying insulin sensitivity/resistance in women with polycystic ovary syndrome (PCOS). Methods: One hundred and seventy-two Korean women aged 18-35 years who were diagnosed with PCOS were included in this study. Fasting-state insulin sensitivity assessment indices (ISAIs) derived from a combination of fasting insulin and glucose levels were calculated for all study participants, and abnormal insulin sensitivity was defined as any of the evaluated ISAIs being out of the established normal range. Correlation analysis was conducted to assess the relationship between the TyG index and other clinical and biochemical parameters. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff value of the TyG index for identifying abnormal insulin sensitivity, and unpaired t-tests were used to compare biochemical parameters between individuals with a TyG index below the cutoff and individuals with a TyG index above the cutoff value. Results: All clinical parameters, except age and other insulin resistance-related biochemical parameters, were significantly related to the TyG index. The ROC curve analysis revealed an optimal TyG cutoff value of 8.126 (sensitivity, 0.807; specificity, 0.683) for identifying abnormal insulin sensitivity. In the comparative analysis, all ISAIs and parameters derived from the lipid profiles differed significantly between the TyG groups. Conclusion The TyG index is a feasible surrogate marker for predicting insulin sensitivity/resistance in women with PCOS.