It is almost universally agreed that there is a variety of terminology currently used for the classification of intraepithelial squamous lesions of the cervix and vulva, which in some instances is ambiguous. The optimal management and welfare of patients with such lesions requires a language accepted and readily understood among gynaecologists, cytopathologists and dermatologists. Moreover, a common system of terminology will encourage standardization and comparability of reports on an international and interdisciplinary basis. This communication studies: (a) the existing systems of terminology and the problems associated with them; (b) the new concepts of precancerous lesions and their relation to the natural history, pathogenesis and treatment; (c) the need to establish a common language between specialists. It is concluded that despite the fact that for the moment there is no perfect system of nomenclature, the recent effort made by experts to adopt an international system for reporting should be supported.