BACKGROUND Human immunodeficiency virus (HIV)-seropositive men who have sex with men (MSM) are at higher risk of human papillomavirus (HPV) infection. This study was conducted to better understand the natural history of type-specific HPV infection in the anus. METHODS A cohort study was conducted among HIV-seropositive MSM in Montreal to investigate acquisition and loss of anal HPV infection. Participants were followed up every 6 months for 3 years for risk behaviors, HIV-related parameters, and HPV testing. RESULTS HPV DNA was detected in 97.9% of the 247 participants at baseline (median, 5 HPV types). The most common types were HPV-16 (38.2%) and HPV-6 (35.3%). Prevalent HPV-16 infections had the lowest clearance rate (12.2 cleared episodes per 1000 person-months [95% confidence interval {CI}, 8.5-17.7]) and a mean retention time of 36 months (95% CI, 32.7-38.8). The highest incidence rates were found for HPV-16 (10.8 new cases per 1000 person-months [95% CI, 8.0-14.7]), HPV-52 (10.8 new cases per 1000 person-months [95% CI, 8.2-14.1]), and HPV-53 (9.8 new cases per 1000 person-months [95% CI, 7.4-13.0]), with cumulative incidences at 36 months of approximately 30%. CONCLUSIONS Multiple HPV types were common in the anal canals of HIV-seropositive MSM. Incidence and clearance rates were not similar among HPV types. Ongoing surveillance of this cohort will help our understanding of the determinants of HPV persistence and progression to lesions.