The expression of specific CD44 splice variants in malignant tumors has been shown to be associated with metastasis and poor prognosis. In previous studies we have detected aberrant expression of the transmembranous cell adhesion molecule CD44 in cervical cancer. Therefore, we now focus on its role in intraepithelial dysplastic lesions of the cervix. Forty-five cervical intraepithelial neoplasias (CIN), grades I to III, were investigated immunohistochemically for three different splice variants of CD44 (v5, v6, and v7-8). A negative correlation of CD44v5 (Kendall correlation coefficient r = -0.25, P < 0.05) expression with the grade of CIN was found. In normal squamous epithelium of the cervix, the staining reaction of CD44v5 was confined to the basal and the parabasal cell layers. In dysplastic lesions a diffuse and weaker staining pattern of the entire epithelium was observed. Our data suggest a loss of CD44v5 epitope during dysplastic transformation. It seems that expression of CD44 splice variants is not a continuous process in the natural history of cervical cancer, and the pattern of CD44 splice variant expression is changed during carcinogenesis.