Among previously untreated cases of invasive carcinoma of the cervix in intact uterus evaluated and treated, primary adenocarcinoma accounted for 20% of the entire group. This incidence is higher than in previously reported series. While the true frequency of this entity is increasing, careful fractional curettage, attention to morphologic characteristics and special stains will distinguish adenocarcinoma from primary endometrial adenocarcinoma. Eight of 10 patients with stage I adenocarcinoma had sterilized hysterectomy specimens after preoperative irradiation. Radiation therapy alone may be adequate for stage I adenocarcinoma.