Objective. The aim of this study was to compare the serum levels of fibroblast growth factor 21 (FGF-21) between patients with polycystic ovary syndrome (PCOS) and control subjects and to assess the possible relation with the hormonal and metabolic parameters. Methods. A total of 91 patients with PCOS and 53 age- and body mass index (BMI)-matched healthy controls were included in the study. We evaluated anthropometric, hormonal and metabolic parameters in all the cases. Serum FGF-21 and high sensitive C-reactive protein (hsCRP) levels were measured by ELISA. Results. Mean fasting glucose and insulin, homeostasis model assessment insulin resistance index (HOMA-IR), triglyceride, total cholesterol, low density lipoprotein cholesterol, total testosterone, dehydroepiandrosterone sulfate (DHEAS) levels were significantly higher in PCOS patients. Serum FGF-21 levels were similar in PCOS (236.8 +/- 171.2 pg/ml) and the control (224.6 +/- 128.9 pg/ml) group (p = 0.654). FGF-21 level had no correlation with BMI, waist circumference, HOMA-IR, hsCRP and lipid parameters. However there was a significant negative correlation between FGF-21 and DHEAS levels (r = -0.309, p = 0.003). Conclusion. FGF-21 levels were similar in women with PCOS compared with those of age- and BMI-matched controls.