Extensive laboratory and epidemiological evidence demonstrate that human papillomavirus (HPV) is the major cause of squamous cervical carcinoma (SCC), its precursor lesions (cervical intraepithelial neoplasia - CIN) and several other benign and malign clinical manifestations including genital warts, condylomata acuminata, Bowenoid papulosis, vaginal, vulvar and anal intraepithelial neoplasia (VIN and AIN) and carcinoma, penile carcinoma and other squamous neoplasias of the head and neck districts. In addition, mother-to-child transmission is probably responsible for recurrent laryngeal and pulmonary papillomatosis in infants. The relevance and high level of scientific interest surrounding HPVs are related to the oncogenic potential of some viral types belonging to this family and the possibility to influence the incidence of various tumour forms likecervical carcinoma, improving the efficacy of specific screening programs or defining preventive strategies like vaccination.