Objective: The measurement of urinary 8-hidroxy- 2'deoxyguanosine (8-OHdG) level by liquid chromatographytandem mass (LC-MS/MS) method in order to determine whether there is an obvious oxidative deoxyribonucleic acid (DNA) damage in patients with polycystic ovary syndrome (PCOS) and its relationship with long term risks. Material and methods: Twenty-eight patients with PCOS diagnosis according to the criteria of 2003 Rotterdam Concensus Conference on PCOS were included in this study and twenty-seven healthy women were included as control group. After collecting first morning urine samples of patients and women in control group, the urinary 8-OHdG level were measured by LC-MS/MS method and the results were expressed as nmol/L. 8-OHdG/creatinine ratio (nmol/mol) was used to compensate the variation of all nucleoside concentration in urine. The patients with PCOS and the control group were compared in terms of the 8-OHdG/creatinine ratio. Results: Statistically, there was not a significant difference between the patients with PCOS and the control group in terms of the 8-OHdG/creatinine ratio (p= 0.533). Conclusion: According to our research, due to an increase of antioxidant and DNA repair capacity, the urinary 8-OHdG/creatinine ratio as a determinant of oxidative stress in patients with PCOS was not different from the level analyzed in healthy women.