Polycystic Ovary Syndrome (PCOS) is a common condition of infertility in females and its major hallmark features are hyperandrogenemia and hyperinsulinemia.Marjoram (Origanum majorana) is traditionally used to restore hormonal balance and to regulate the menstrual cycle and was confirmed to have positive effect on the hormone profile of females with PCOS. The present study was conducted to evaluate the effect of marjoram on Letrozole induced-PCOS.Twenty-one female ratswere used and divided into three groups (n = 7/each): (group I): negative control group fed on basal diet. Group II and III were orally administrated LTZ 1mg/kg/day for 3 weeks. Group II kept as positive control group (PCOS-group) and fed on the basal diet only. While, the remaining group was fed on supplemented diet with 1.5% of marjoram. The obtained resultsrevealed thatfeeding PCOS-rats on 1.5% of marjoram hadsignificant increase (p˂0.05) in Estradiol (E2) and decreased (p˂0.05) in serum levels of insulin and glucose,luteinizing (LH), Total testosterone,Dehydroepiandrosterone sulfate (DHEA-S) hormones, andactivity of liver enzymes (AST, ALT, and ALP), while there is no significant change in Follicle-stimulating hormone (FSH) and Progesterone hormone level as compared to the positive group of rats. Microscopically, results showed improvement in Graffian follicle and corpus luteum in the groups of PCOS rats and were fed on diet supplemented with 1.5% of marjoram as compared to the positive control group. Finally, the existing study illustrated that licorice and flaxseed could improve PCOS syndrome via affecting the serum levels of different hormones and morphology.