Asafoetida is a gum derived from Ferula assa-foetida, which is used in traditional Iranian medicine to treat some reproductive system disorders. The effects of asafoetida on ovarian tissue, expression of certain genes associated with polycystic ovary syndrome (PCOS), and levels of liver, kidney, and blood cell factors after treatment in a rat model were investigated. Thirty rats were divided into five groups: normal, polycystic, and treatment with three doses of asafoetida (12.5, 25, and 50 mg/kg for 3 weeks after PCOS induction). PCOS was induced by letrozole at a dose of 1 mg/kg administered orally for 3 weeks. Blood samples were taken, and the ovaries were removed and prepared for histomorphometric examination. Liver and kidney parameters were measured. The mRNA expression levels of luteinizing hormone receptor, CYP11A1, adenosine monophosphate-activated protein kinase, adiponectin, and adiponectin receptors 1 and 2 were also measured by real-time polymerase chain reaction. The levels of liver, kidney, and blood parameters did not significantly differ between the treatment groups and the control group. At doses of 25 and 50 mg/kg, ovarian histopathology, especially the thicknesses of the theca and granulosa layers, was significantly improved relative to the PCOS group. The expression of target genes also improved in the 25 and 50 mg/kg treatment groups. Asafoetida can be used to treat PCOS as a complementary approach to conventional therapies. Asafoetida appears to act by regulating and activating metabolic and ovarian cycle enzymes.