Polycystic ovary syndrome (PCOS) is one of the common endocrine disorders among women. Its prevalence increases up to 15% based on the Rotterdam criteria. It has been extensively studied for over 10 years that, among many factors, oxidative stress (OS) is a potential factor in the etiology of PCOS. This study aims to investigate the role of OS in the pathogenesis of PCOS. An examination was made on 30 patients with PCOS and 30 healthy adolescent and young adult women aged between 15-22 years. The diagnosis of PCOS was established considering the recommendations of the last Amsterdam ESHRE/ASRM conference. Basal hormone levels in the early follicular phase, fasting glucose and insulin values, serum lipid profiles, serum albumin, ischemia-modified albumin (IMA), total thiol, native thiol, and disulfide levels were recorded as the patients' main parameters. Albumin, IMA, thiol, and disulfide levels were compared between the PCOS and control groups. The albumin level was statistically significantly higher in the PCOS group than in the control group. A negative correlation was detected between serum CRP levels and serum albumin, native thiol, and total thiol levels. Total and native thiol values were statistically significantly lower in the BMI overweight group. In conclusion, in the present study in which OS markers in 30 PCOS patients and 30 healthy adolescent and young adult women were examined, the serum albumin level was statistically significantly higher in the PCOS group compared to the control group, and IMA, total and native thiol and disulfide levels did not differ between the groups. For a clear understanding of the place of OS in the diagnosis of PCOS, it should be supported by studies involving larger patient groups and adult women of reproductive age.