**1. Introduction**

Human papillomaviruses (HPVs) are infectious agents responsible for emergence of anogen‐ ital subclinical and clinical infections. HPV infections are the most common sexually trans‐ mitted infections worldwide. More than 100 HPV genotypes have been catalogued so far and from these, over 40 genotypes infect mucosa of anogenital tract and other mucosal areas. The epidemiology of anogenital HPV infections has been well described, especially cervical infections in young women and there are also many epidemiologic data among adults of different age and of different regions of the world. HPV is now recognized as a necessary cause for the apparition of cervical cancer in women, and is responsible for a substantial proportion of many other anogenital neoplasms (anal, vaginal, vulvar and penile cancers), and a nonnegligible portion of head and neck cancers (oral cavity, pharynx, and larynx). HPV is also responsible for the development of benign lesions such as *condyloma acuminata* (genital warts). Clinical HPV infections are responsible for substantial morbidity and invoke high costs associated with the treatment of clinically relevant lesions. This chapter will review epidemi‐ ology of HPV infections affecting the anogenital tract of men and women.
