Background: Having low-grade chronic inflammation such as elevated C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) plays a crucial role in polycystic ovary syndrome (PCOS). This study aimed at investigating the therapeutic effects of curcumin on IL-6, CRP and TNF-α and symptoms of polycystic ovary syndrome. Methods: In this research, 72 female adult Wistar rats were divided into control (n=12), PCOS (n=12) and curcumin-treated PCOS groups (n=48). PCOS was induced by injection of estradiol valerate (2 mg/kg- one-step). PCOS rats were divided into control and experimental groups which received daily intraperitoneal injection of curcumin. After 60 days of syndrome induction, ovaries were collected for histological and immunohistochemical evaluations. Serum IL-6 and CRP was detected by the ELISA kit. Data were analyzed using In-Stat 3 via one-way analysis of variance (ANOVA) and p<0.05 was considered statistically significant. Results: Histological studies showed a significant reduction in thickness of theca layer and increase in the number of corpus luteum (CL) diameter in the curcumin-treated group compared with the PCOS group; also inflammatory markers such as IL-6 and CRP significantly decreased in groups treated with curcumin compared with PCOS groups. Regarding immunohistochemical analysis, the expression of TNF-α in granulosa layer and follicular fluid of follicles and ovarian cysts in PCOS group was more than the control group's expression. However, expression of this factor in the ovaries treated with curcumin was decreased. Conclusion: This study showed that the anti-inflammatory and antioxidant effects of curcumin on PCOS may be due to its inhibitory effect on expression and levels of TNF-α, serum IL-6 and CRP.