Squamous cell carcinomas of the endometrium, either primary or secondary extending from the cervix, are rare. We report a 52-year-old woman with squamous cell carcinoma in situ of the cervix associated with squamous cell carcinoma in situ of the endometrium. The patient had received pelvic cobalt therapy 10 years earlier. She presented to the hospital with discomfort in the lower abdomen. Examination revealed vaginal stenosis and pyometra. After cervical cytology and a biopsy showing squamous cell carcinoma in situ, a wide abdominal hysterectomy with bilateral salpingo-oophorectomy (Wertheim modification) was performed. The unusual presentation of cervical carcinoma with a history of previous radiation treatment suggests the need for performing more cytologic and histologic studies on these patients, because of the risk of developing a secondary malignancy.