UrotensinII (UII), one of the most potent vasoconstrictor proteins, may be associated with insulin resistance. The objective of our research was to determine the level of UII in sera of patients with PCOS and to investigate the relationship between UII and insulin resistance in patients with PCOS. Fourty seven PCOS patients and 42 healthy women were included in the study. Serum fasting glucose, insulin, UII, free testosterone and hs-CRP levels of the patients were examined. The HOMA-IR formula was used to calculate insulin resistance. Insulin sensitivity was calculated by using the QUICKI-IS formula. The two groups did not show any a significant difference in terms of age and BMI (p>0.05). Serum UII, hs-CRP, insulin levels and the HOMA-IR were significantly higher in the patients with PCOS (p<0.05). In the analysis of the correlation, UII and HOMA-IR showed statistically significant, moderately strong and positive correlation(r = 044, p<0.001). UII and QUICKI-IS showed statistically significant, moderately strong and negative correlation(r = -0.44, p<0.001). Also, a significant and positive correlation was found between with UII and hs-CRP(r = 0.51, p<0.001). Our study data suggested that UII may have a role in the pathophysiology of insulin resistance and increased cardiovascular risk, which are commonly found in patients with PCOS.