Primary vaginal adenocarcinomas are one of the rarest malignant neoplasms, which develop in the female genital tract. Because of the extremely low incidence, their clinical and pathologic characteristics are still obscure. Recently, we experienced a case of vaginal adenocarcinoma that appeared 7 yr after hysterectomy because of cervical intraepithelial neoplasia. The patient, a 65-yr-old obese woman, was diagnosed as having adenocarcinoma in the vaginal stump and was treated by simple tumor excision and radiation. Immunohistochemical and molecular biologic examinations indicated a potential association with human papilloma virus infection in the development of the vaginal adenocarcinoma. There has been no evidence of recurrence for 3 yr after the operation.