The aim of this study was to determine the effect of ursodeoxycholic acid (UDCA) treatment on a polycystic ovary syndrome (PCOS) rat model. Thirty-two female Wistar-Albino rats were randomly divided into four groups as follows - group 1: sham group (n: 8), group 2: letrozole-induced PCOS group (n: 8), group 3: letrozole-induced PCOS plus metformin-treated (500 mg/kg) group (n: 8) and group 4: letrozole-induced PCOS plus UDCA (150 mg/kg)-treated group (n: 8). Histopathologic examination of the ovaries, circulating estrone (E1), estradiol (E2), testosterone, androstenedione, glucose, insulin and lipid profiles were evaluated. Histopathologic examination results revealed that groups 3 and 4 had significantly lower cystic and atretic follicles compared to group 2. Besides, group 4 had significantly higher antral follicles than group 2 (8.5 +/- 2.9 versus 5.4 +/- 1.1; p: 0.001). Furthermore, total testosterone (4.9 +/- 2.8 versus 8.8 +/- 2.9; p=0.004) and insulin levels were significantly lower in group 4 compared to group 2 (1.7 +/- 0.08 versus 2.1 +/- 0.5; p = 0.02). However, lipid parameters, E1, E2, glucose and HOMA-IR were comparable between the groups. Our study results demonstrated that UDCA therapy improves ovarian morphology and decreases total testosterone and insulin levels.