Papillomaviruses (PVs) are naked icosahedral viruses with circular double-stranded (ds) DNA genomes. They are quite stable in the environment. PVs have a strict tropism for epithelial cells and their replication induces benign hyperplasia of the skin to form common warts. Productive infection of PVs requires differentiation of keratinocytes thus these viruses cannot productively infect transformed cells. PVs are quite host specific and cross-species transmission is very rare. Over 100 types of human PVs (HPVs) have been identified. Infection by a small set of high-risk HPVs can lead to development of anogenital cancers. Vaccines that target high-risk HPVs are proving useful in decreasing the incidence of cervical cancer.