In recent years, there have been major advances in our understanding of the biology and natural history of Human Papilloma Virus (HPV). Most papillomavirus infections are transmitted by close contact of either skin to skin or mucosa to mucosa. Sexual intercourse is not a requirement for genital HPV infection. Digital-oral infections occur and there is evidence that digital-genital and oral-genital contacts can result in the transmission of HPV, although in a relatively low percentage. Vertical transmission from mother to fetus is a common route of infection; in fact, it is recognized that more than 80% of infants born from mothers infected with genital HPV will be positive for HPV DNA determination in the nasal-pharyngeal region and oral mucosa. Women with transient infections often develop cytological abnormalities that take place while there is active HPV replication. This occurs because productive HPV infections result in cytological abnormalities in infected epithelial cells. The strong association between the risk of HPV infection and increased immune suppression, supports a direct biological effect of Human Immunodeficiency Virus (HIV) infection on the natural history of HPV.