Sixty-six types of human papillomaviruses have been identified to date. These viruses are of increasing interest to the scientific and medical communities. There are 14 types that are site specific for the human genitalia. Of highest importance is the epidemiologic and biologic association of certain human papillomavirus types to the development of lower genital tract cancers in women and men. Human papillomaviruses have also been implicated as the sexually transmitted agent responsible for genital condylomas, abnormal Papanicolaou smears, precancerous changes, and invasive squamous and adenocarcinomas of the lower genital tract. Cytologic screening and detection of human papillomavirus-related diseases and their treatment are major concerns of both clinicians and their patients.