Abstract: The present research was carried out in the animal facility of the Department of Biology, College of Science, University of Al-Qadisiyah, from January 20, 2023, until June 27, 2023. This study sought to observe the effect of varying dosages of nano-silica (SiO2 NPs) on the gene expression of the genes encoding follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in female rats. The findings indicated marked reduction (P<0.05) in the gene expression of both FSH and LH within the treatment groups (T1: 100 mg/kg, T2: 150 mg/kg, and T3: 200 mg/kg) relative to the control group. The most marked reduction was noted within the T3 group, suggesting a dose-dependent response. Histopathological exam of the ovaries, oviducts, and uterus established various structural changes within the dose groups. The ovaries of the T2 and T3 experimental groups had granulosa cell degeneration, massive congestion, and follicular cell deterioration. The oviducts of the T1 experimental group had epithelial lining destruction and considerable congestion, but the uterine sections of the T2 and T3 experimental groups were considered histologically unremarkable. The results imply that the administration of nano-silica may cause widespread alterations in the gene expression of reproductive hormones, potentially resulting in compromised reproductive function and fertility in female rats. Further research is needed to clarify the fundamental mechanism and long -time effects of nano-silica exposure on the female reproductive system.