We report diagnosis and treatment problems encountered in 4 cases of adenocarcinoma in situ (AIS) of the uterine cervix. The patients' ages ranged from 24 to 45 years. In 2 cases, Pap smears revealed strips of cells showing crowded nuclei and pseudostratification of AIS. In 3 cases, the diagnosis of AIS was confirmed from a colposcopically directed biopsy and, in the last case, from a surgical cone biopsy. In 3 cases, AIS was found to be associated with cervical squamous intraepithelial neoplasia. In all cases, it was difficult to rule out an early invasive adenocarcinoma. Three patients underwent total abdominal hysterectomy. The topographic data of lesions, notably the presence of endocervical AIS in hysterectomy specimen realised 4 years after conization, and a review of literature lead us to propose hysterectomy as a basic treatment. If conization is chosen, it should be cylindrical with adequate diameter and height.