Objective: Assess a status of thyroid function and thyroid disorders in subjects with polycystic ovarian syndrome. Methods: This prospective hospital based case-control study that the most cases being attending outpatient clinics of Obstetrics, Gynecology, and infertility clinic of Baghdad Teaching Hospital in age group 13–45 years, with complaints of hirsutism and/or oligomenorrhea or infertility. 50 patients with polycystic ovary syndrome (PCOS) recruited to evaluated thyroid functions and morphology; age-matched women without PCOS studied as a control group. Results: This study enrolled 70 patients including 50 patients known cases of PCOS as cases group, and 20 patients do not have PCOS as a control group. Thyroid hormone T3 and T4 did not vary significantly between the two groups (P > 0.05), higher mean TSH level (3.9 compared to 3.1 µIU/L) (p= <0.001), LH level statistically significant (P=<0.001), FSH statistically not significant (p=0.007), and BMI (Kg/m2) was higher in patients group than control (p=<0.001). Conclusion: We demonstrate higher prevalence of euthyroid (subclinical hypothyroidism) in patients with PCOS.