The Central Netherlands Registry (CNR) of women with vaginal or cervical clear cell adenocarcinoma (CCAC) was established in 1985. An overview is presented of clinical and pathologic data of 55 patients who were registered at the CNR until July 1, 1988. All Netherlands Departments of Pathology (NDP) maintain a patient registry and 95% of the Institutes are connected with a Central Archive via a computer network. The histologic slides and clinical status were reviewed at the CNR. Twenty-five tumors were classified as vaginal carcinoma and 30 as cervical carcinoma. The mean age of the patients was 22 years. Fifty-five percent of patients (63% of patients with known maternal history) were exposed to diethylstilbestrol (DES) in utero. The majority of cases was initially diagnosed after 1980. Cytologic examination before the initial histologic diagnosis indicated that cervical tumors were detected in 80% of cases, but vaginal tumors were detected only in 33% of cases. It was concluded that an examination of DES-exposed women should consist of colposcopic inspection of the cervix and vagina, cytologic examination of the cervix and four quadrants of the vagina, and careful palpation of the cervix and the entire vaginal wall. The most important prognostic parameter for patients with CCAC was stage and grade of nuclear atypia. The results of a statistical analysis showed that these features were the most effective to distinguish between nonsurvivors and patients surviving more than 5 years.