ABSTRACT: The experimental immune oophoritis (EIO) model was used to study the functional relationship between the ovary and organs of the immune system. EIO was developed in Balb/c mice by twofold subcutaneous injection of saline ovarian extract in complete Freund's adjuvant. The ovary, thymus, and spleen were investigated histologically, histoautoradiographically, and electromicroscopically on days 7, 14, 21, and 28 after immunization. EIO was manifested by massive atresia of follicles and perivascular mononuclear cell infiltration. The appearance of the germinal center like structures in the thymus and increased T cell mitotic activity and B cell stimulation in the spleen pointed out that EIO is mediated both by T and B cells.