Background: Endocrine conditions that impact women define polycystic ovary syndrome. Previous studies have demonstrated a connection between PCOS and insulin intolerance, oxidative stress, and immune system dysfunction. Additionally, some reports have indicated that propolis has antioxidant properties and that chitosan nanoparticles have beneficial effects on the reproductive system. The goal of the present study is to compare metformin (Met) to chitosan-propolis nanoparticles and explain how they protect against a rat PCOS model caused by estradiol valerate (EV). (as a control treatment). Methods: In order to cause PCOS in rodents, a single subcutaneous injection of estradiol valerate was used, followed by a 42-day oral administration of 500 mg/kg of chitosan-propolis nanoparticles. Four sets of rats were created: the control, PCOS, metformin (PCOS and 150 mg/kg metformin), and chitosan-propolis nanoparticle (PCOS and 500 mg/kg chitosan-propolis nanoparticle) groups. The histopathological examination of the ovaries and measurement of serum ferctors were performed on all of the animals. Estradiol valerate caused PCOS, but chitosan-propolis nanoparticle therapy reversed it. Results: After chitosan-propolis nanoparticle intervention, the body weight and ovarian morphology had improved, and the serum biochemical parameters, including esretogen, progestron, vitamin D, calcium, and the insulin resistance index, had been corrected. These EV-induced changes include decreased SOD activity, elevated MDA levels, and evidence that oxidative stress was increased by EV when chitosan-propolis nanoparticle/Met were administered for 42 straight days. Additionally, certain relative mRNA transcripts, including those for the MCP, IL18, and CRP genes, were markedly upregulated in EV-treated animals. These findings unequivocally demonstrate the beneficial effects of chitosan-propolis nanoparticles/Met in inflammatory disorders. Conclustion: Together, the study's end findings, which are presented here, are consistent with the hypothesis that chitosan-propolis nanoparticle/Met offered protective activity against the harmful effects of EV. Although ameliorative effects may have been implicated, the primary pathway or pathways still need to be clarified.