The female genital tract is usually involved with lymphoma as part of disseminated disease. Primary lymphoid neoplasms of the female genital tract are rare; the frequency was reported to be 2% among extranodal lymphomas in women. Most of the time, primary female genital tract lymphoma occurs in the ovary and cervix, whereas endometrial lymphoma is extremely rare. The case of an 89-year-old patient that presented with postmenopausal bleeding is reported. An endometrial polypoid formation was found on hysteroscopic examination and the biopsy revealed a diffuse large B-cell lymphoma. Total abdominal hysterectomy and bilateral salpingo-oophorectomy were surgically performed. The histologic diagnosis was primary diffuse large B-cell lymphoma of the endometrium. Adjuvant therapy was not performed. Five months after initial diagnosis, the patient died. Only a few case reports of primary endometrial lymphoma have been published; therefore, information concerning etiologic factors, histologic type, treatment and prognosis is limited.