While there are studies postulating a model of synergism between human papillomavirus (HPV) and herpes simplex virus (HSV) in cervical carcinogenesis, the frequency of anal herpes as well as its association with anal squamous intraepithelial lesions (ASILs) has been understudied in men. This study evaluates the frequency of HSV changes in anal Pap smears and its association with ASILs in a high-risk population. A computerized search for specimens associated with anal cytology that had positive findings of HSV was performed. The electronic medical records were examined for past diagnosis of herpes, HSV serology prior to or after cytology, and if the patient received treatment after cytologic diagnosis of HSV. Of the 470 anal Pap smears (Thin-prep) examined, seven had cellular changes consistent with HSV infection. All patients were asymptomatic human immunodeficiency virus (HIV) positive males with no prior HSV serology tests. Two patients had prior diagnoses of HSV infection. Cytologic abnormalities were identified in 86% ranging from atypical squamous cells of undetermined significance to high grade squamous intraepithelial lesion. Three patients were treated after the HSV cytologic diagnosis. The frequency of HSV changes in anal Pap smear is low (1.48%), but the presence of concomitant cytologic abnormalities is high (86%). While our findings suggest the possible role of HSV as a HPV co-factor in ASILs, larger studies are needed to support this. Identification of HSV infection on anal Pap smear is important for institution of patient treatment and subsequent reduction of transmission. Diagn. Cytopathol. 2014;42:487–490. © 2013 Wiley Periodicals, Inc.