This article describes the epidemiology of mucosal human papillomavirs (HPV) in adults and children, its mode of transmission and its associated diseases. Over 40 genotypes of HPV infect the epithelial lining of the anogenital tract and other mucosal areas of the body. HPV is the most common sexually transmitted infection globally, with high prevalences found in both females and males. The predominant route of transmission is via sexual contact, although mother-to-child transmission is also possible. HPV infection may exist asymptomatically or may induce the formation of benign or malignant tumours in the genital, oral or conjunctival mucosa. Although most infections clear spontaneously, those that persist result in substantial morbidity and invoke high costs associated with the treatment of clinically relevant lesions. Some 13-18 mucosal HPV types are considered to have high oncogenic potential. HPV is recognized unequivocally as the main causal factor for cervical cancer, and is further responsible for a substantial proportion of many other anogenital neoplasms and head and neck cancers. Infections with HPV types that have low oncogenic risk, such as HPV-6 and 11, are associated with benign lesions of the anogenital areas known as condylomata acuminata (genital warts), oral papillomas, conjunctival papillomas, as well as low-grade squamous intra-epithelial lesions of the cervix. Perinatally acquired HPV can also cause recurrent respiratory papillomatosis in infants and young children. The implementation of HPV vaccination therefore has the potential to prevent a substantial proportion of HPV-related disease in the future. Copyright 2009 S. Karger AG, Basel.