ABSTRACT: Polycystic ovary syndrome (PCOS) is a disorder characterized by hyperandrogenism, oligo- or anovulation, and/or polycystic ovary. It frequently presents with dyslipidemia and insulin resistance. Recent studies have shown that the white adipose tissue-derived asprosin is elevated in humans with insulin resistance. Because many PCOS patients have a propensity to develop dyslipidemia and/or insulin resistance, asprosin metabolism could be dysregulated in PCOS patients. Accordingly, we investigated serum levels of asprosin, irisin, GIP, androgens, LH, glucose, insulin, and lipids as well as HOMA-IR, QUICKI and ISI Matsuda in a cohort of 444 PCOS patients and 156 controls. Patients were stratified based on metabolic syndrome risk factors (ATPIII [+] and [-] groups), or BMI (overweight and lean groups). The irisin level was significantly correlated with body weight, SBP, DBP, Ferriman-Gallwey score, and levels of TSH, triglycerides, glucose and insulin in the overall population, and was elevated in ATPIII(+) and overweight PCOS patients compared to corresponding controls. By contrast, asprosin levels in PCOS, ATPIII(+), or overweight patients were similar to those of corresponding controls. This finding indicated that the regulation of irisin, but not asprosin, metabolism is abnormal in PCOS patients, and this metabolic characteristic is distinctly different from that of diabetes patients.