Background and Objective: Sesame is one of the plants with many applications including production of sesame oil, ground sesame seed, sweets and bread in food industry. Alongside, it is used to boost strength and body foundation due to its nourishing properties. Whereas the likelihood of teratogenicity for this seed has been discussed during the pregnancy, the present study was carried out to investigate the possible effects of sesame seeds on the Oogenesis.Materials and Methods: In this expermental study, the mice were retained under appropriate laboratory conditions and were divided into five groups of control, sham, empirical 1, 2, and 3. The mice of the control group were supplied merely with water and special mouse food, while the mice of sham group were given 0.5 cc of distilled water daily for 10 days. The mice of three empirical groups 1, 2 and 3 were supplied with doses of 0.0818, 0.1636 and 0.818 (mg/Kg of body mass) sesame, respectively, mixed with 0.5 cc of distilled water by oral gavage. The mice in all groups were dissected after the completion of the gavage and the texture of their right and left ovaries was separated and examined after the process of alcohol supply, molding, shredding as well as painting.Results: Following the administration of sesame seed, the side effects were investigated such as increase in the number of follicle types, increase in the diameter and number of primitive and primary follicles, decrease in the diameter of other follicles, increase in the length and the diameter of ovaries and increase in the number of yellow bodies.Conclusion: The above results assert the harmful effect of sesame seeds on the ovary and on the process of Oogenesis.