The presence of papillomaviruses in epithelial-derived cancers from several animal species has led to the speculation that these viruses may also have a pathogenic role in the development of certain human carcinomas, particularly those associated with the anogenital tract. Recently, human papillomavirus (HPV) DNA has been detected in epithelial-derived cancers, both cutaneous and metastatic, from patients exhibiting the rare, chronic flat wart disease, epidermodysplasia verruciformis (EV). Except for patients exhibiting this chronic wart syndrome, the association of HPV genomes with human epithelial cancers has not been demonstrated. In an attempt to delineate the association and possible involvement of papillomaviruses with human anogenital carcinomas, we have begun an analysis of these cancers for the presence of HPV-specific nucleotide sequences by using highly sensitive hybridization procedures capable of detecting distantly related papillomaviruses at low copy number. Here we demonstrate the presence of HPV DNA in several types of anogenital tumours: Bowenoid papulosis, carcinoma in situ, and verrucous carcinoma. These data indicate that HPV can be detected in several types of premalignant and malignant tumours, supporting the contention that this group of viruses may be involved in the development of certain types of human epithelial-derived cancers.