The prevalence of human papillomavirus (HPV) induced lesions and a significant increase in the incidence of anal cancer in patients infected by HIV mean that systematic screening is now necessary in this population. Risk factors, other than homosexuality and HIV infection, are: multiple partners and a history of sexually transmitted infections. In 2008 it is recommended that screening should involve a complete proctological examination with anoscopy, performed by an experienced operator. Frequency of recurrence means that such patients should be regularly monitored.