Background Our objective was to identify virological and serological predictors of anal high-grade squamous intraepithelial lesions (HSIL) in human immunodeficiency virus (HIV)-positive men who have sex with men (MSM). Methods HIV-positive MSM were recruited from a longitudinal study during which anal self-swabs and serum were collected at up to 5 bi-annual visits. Swabs were human papillomavirus (HPV) genotyped, and the type-specific HPV viral load in the anal swabs was determined. Serum antibodies to the E6, E7, E1, E2, and L1 proteins of 7 high-risk HPV (hrHPV) types and HPV6 and 11 were analyzed. The participants who had a high-resolution anoscopy after the last study visit were included in the current analysis. Anal HSIL was diagnosed by histopathological examinations of anal biopsies. The causative HPV type of anal HSIL was determined in whole tissue sections (WTS) and by laser capture micro-dissection if more than one HPV-type was found in WTS. Multivariable logistic regression was used to study whether persistent anal HPV infections, HPV viral loads, and seropositivity for HPV were predictors of anal HSIL, either in general or caused by the concordant HPV type. Results Of 193 HIV-positive MSM, 50 (26%) were diagnosed with anal HSIL. HrHPV persistence in anal swabs was common, varying by hrHPV type between 3-21%. Anal HPV persistence was the only determinant independently associated with anal HSIL, both in general and by concordant, causative HPV type. Conclusions Persistent HPV infections were strongly associated with anal HSIL, in general as well as for the concordant HPV type.