Background: Infection with human herpesvirus 8 (HHV-8) is common among men who have sex with men (MSM) in North America and Europe and is also found to be endemic in some regions of South America. Little is known about HHV-8 prevalence and its correlates among MSM in the Andean region. Methods: We assessed HHV-8 seroprevalence among 497 MSM recruited for the 2002 Peruvian HIV sentinel surveillance program using a combined HHV-8 enzyme immunoassay and immunofluorescence assay algorithm. Logistic regression analysis was used to estimate odds ratios (ORs) and their 95% confidence intervals (CIs) to determine the association between selected covariates and HHV-8 seropositivity. Results: One hundred thirty-one (66.5%, 95% CI 63.1% to 69.9%) of 197 HIV-infected and 80 (26.7%, 95% CI 24.4% to 29.0%) of 300 HIV-uninfected MSM had serologic evidence of HHV-8 infection. Factors independently associated with HHV-8 infection were education <12 years (OR 1.7, 95% CI 1.1 to 2.7), anal receptive sex with the last partner (OR 2.0, 95% CI 1.2 to 3.3), self-reported sexually transmitted infection symptoms during the last year (OR 1.9, 95% CI 1.2 to 3.0), coinfection with HIV (OR 4.2,95% CI 2.8 to 6.4) and chronic hepatitis B (OR 4.9, 95% CI 1.5 to 15.8). MSM with long-standing HIV infection were more likely to have serologic evidence of HHV-8 infection when compared with men with recently acquired HIV (OR 3.8, 95% CI 1.7 to 9.1). Conclusions: HHV-8 infection is common among both HIVinfected and HIV-negative MSM in Lima, Peru. HHV-8 seropositivity is correlated with anal receptive sex, self-reported sexually transmitted infection symptoms, and HIV infection among these MSM and thus seems to be sexually transmitted. HHV-8 infection seems to be acquired after HIV infection, suggesting that future studies should evaluate the mode of HHV-8 transmission and prevention strategies among HIV-uninfected MSM.