Of the >170 HPV types, most anal cancers (and cervical cancers) are caused by two high-risk HPV types: 16 and 18 that are responsible for 66% and 5% of anal cancers, respectively. HPV lesions caused by low-risk types include genital warts, of which 90% are caused by HPV types 6 and 11. Prevention strategies for anal cancers have emerged that are analogous to strategies used in cervical cancer screening, in that the aim is to identify precursor lesions which can then be removed before progression to cancer. Screening and detection rely on a combination of anal cytology (Pap smear), anal HPV detection and high-resolution anoscopy (HRA). Despite the clear evidence indicating the benefit of screening and treatment procedures in cervical cancer screening, no rigorous studies have assessed such strategies in anal cancer prevention in men or women.