<p>Background: Saffron petals have traditionally been used to treat a variety of diseases, such as gynecological diseases, primary dysmenorrhea, and premenstrual syndrome. Polycystic ovary syndrome (PCOS) is a kind of gynecological disease that causes infertility, menopausal and urogenital disorders and saffron petals seem to be an efficient treatment for such disorders.<br /> Methods: NMRI mice (total=60, each group n=12) were divided into control, PCOS, and the treatment groups. PCOS and treatment groups were injected with testosterone enanthate (TE=1 <em>mg/kg</em>). After 4 weeks, the treatment group was treated with Saffron Petal Extract (SPE) for 14 days. Ovary and blood samples were collected for histological and serological analyses, and expression of NF-&kappa;B, NF-&kappa;B p65, and I&kappa;B genes was analyzed. Finally, data were analyzed using one-way ANOVA (p&lt;0.05).<br /> Results: In this study, the number of corpus luteum decreased in PCOS mice (p&lt;0.001) but increased with SPE treatment (p&lt;0.05, p&lt;0.01, p&lt;0.001). The number of cystic follicles increased in PCOS mice (p&lt;0.001), but decreased with SPE treatment (p&lt;0.05, p&lt;0.001). TNF&alpha;, IL1&szlig;, IL6, IL18, and CRP levels increased in PCOS mice (p&lt;0.001), but decreased following SPE treatment (p&lt;0.05, p&lt;0.001). Glutathione (GSH) and glutathione S-transferase (GST) serum levels decreased in PCOS mice (p&lt;0.001), but increased with SPE treatment (p&lt;0.05, p&lt;0.001). The transcriptional level (s) of NF-&kappa;B, NF-&kappa;B p65, I&kappa;B genes changed in PCOS condition (p&lt;0.001), and were regulated by SPE treatment (p&lt;0.05, p&lt;0.01 and p&lt;0.001).<br /> Conclusion: The present study shows that SPE improved the PCOS symptoms in mice via increasing antioxidant factors and reducing inflammatory markers in serum.</p>