Clinically, bone marrow transplantation (BMT) is associated with significant posttransplantation gonadotoxicity. This deficit has been mainly attributed to chemotherapy and radiation, but gonadal damage also appear to be associated with graft-versus-host disease (GVHD) following BMT. However, there have been no reports of verifying this with an experimental animal model using the histological analysis of male genitals including the testis and accessory genital glands following BMT. In this study, we examined whether transplantation of bone marrow cells of donor female mice to male recipients induce GVH-like reaction and affect male reproductive organs. In the result, regarding testis and epididymis, no lymphocytes were detected in the control group and homosexual BMT group, whereas some lymphocytes were detected in a portion of intersex BMT group. In particular, lymphocyte infiltration accompanied by glandular structure were observed in intersex BMT group in preputial gland that is well developed in male mice. Furthermore, cytokines examination revealed that production of TNFα, IL-1 and IFNγ had increased in the intersex group. These results indicate that female immune cells recognize the male genital glands as foreign antigens and induce the inflammation.