Objective: This study was conducted to evaluate the effect of Sargassum ilicifolium on testosterone-induced polycystic ovary syndrome (PCOS) in rats.Methods: Female Wistar albino rats were divided into 6 groups consisting of 6 rats each. PCOS was induced in all the animals except normal group on the administration of testosterone (2 mg/100 g) for 21 days daily. After PCOS induction, the standard group rats were treated with clomiphene citrate (CC) (1 mg/kg. p.o.). The test groups were treated with 100, 200, and 400 mg/kg of ethanolic extract of S. ilicifolium orally, and normal animals were administered 2% carboxymethyl cellulose (2 ml/kg), respectively, for 21 days during induction and treatment period various parameters such as estrus cycle, histopathology, hormonal, and biochemical assays have been evaluated. Further to confirm the enhanced fertility rate, the rats were mated, and the litter size was observed. Results:The results revealed the normalcy in estrus cycle, hormonal, biochemical, and histopathological parameters. The litter size was increased significantly compared to control. Conclusion:Overall, from the obtained results, it is determined that the S. ilicifolium exhibited a good antiandrogenic effect by reducing the testosterone levels in PCOS-induced conditions.