Human papillomavirus (HPV), Epstein-Barr virus (EBV), and Kaposi sarcoma-associated herpes virus (KSHV) may promote oral cancers, especially among immunosuppressed individuals. The aims of this study were to examine whether demographic characteristics, medical history, sexual behaviors, substance use, CD4+ T-cell count, HIV viral load, and HPV vaccination were associated with HPV, EBV, and KSHV infection and viral load. Multivariable modeling using logistic or linear regression examined associations between independent variables and infection or viral load, respectively. Among 272 HIV-infected 12-24-year-old youth, 19.5% were positive for oral HPV, 88.2% for EBV, and 11.8% for KSHV. In multivariable models, recent marijuana use (OR 1.97, 95%CI 1.02-3.82) and lower CD4+ T-cell count ( 400 vs.