Oncogenic human papillomaviruses (HPVs) are associated with oropharyngeal squamous cell carcinoma (SCC). Infection with human immunodeficiency virus (HIV) increases susceptibility to opportunistic infections and viral-promoted cancers. The prevalences of HPV, herpes simplex virus (HSV), Epstein-Barr virus (EBV), and human herpesvirus-8 (HHV-8) have not been established for head and neck squamous cell carcinoma in HIV-positive patients (HIV+ HNSCC). We have observed that HIV+ HNSCC tend to contain numerous multinucleated tumor giant cells, this finding has not been described previously. The goal of this study is to test for these oncogenic viruses in a small cohort of retrospectively identified patients with HIV infection, and to compare histologically these cancers to a control group of HNSCC patients. Tumors were reviewed histologically and compared to a control group of 102 patients with HNSCC (serologically untyped or HIV negative). Polymerase chain reaction (PCR) was performed on formalin-fixed, paraffin-embedded HIV+ HNSCC samples from combined 25 patients in two institutions. In situ hybridization was performed to identify EBV (EBER) and immunohistochemistry was performed to detect HSV-1, HSV-2, HHV-8, and HIV-related proteins (Nef, p24). The study sample consisted of 34 HIV+ patients with HNSCC from Montefiore Medical Center, and six HIV+ HNSCC patients from Hospital Clinic, University of Barcelona; 24 (60%) men and 16 (40%) women. The larynx was most commonly involved (65%, n = 26); followed by the oropharynx (22.5%, n = 9). Four carcinomas arose from the oral cavity (10%) and one from the nasal cavity (2.5%). Histologically, multinucleated tumor giant cells were more common in the HIV+ group (39/40, 97.5%) than the control group (27/102, 26%, p 0.001, chi-square). HPV was detected in 6 of 25 (24%) HNSCC tumors by PCR, five were typed as HPV 16 and one as HPV 26/69; five of these tumors (83%) were located in the oropharynx. EBV, HSV-1, HSV-2, and HHV-8 were detected only infrequently in tumor cells. Nef protein was detected in tumor cells in 7 of 21 (33.3%) cases; p24 was not detectable in 6 tumors studied. There were no significant associations between HPV positive tumors and co-infections with other viruses. This study is consistent with other reports that suggest an increased incidence of laryngeal carcinoma for HIV+ patients. HPV was detected in 24% of HIV+ HNSCC, however, the number of tumors with amplifiable DNA (n = 25) is too small to allow for conclusions. EBV, HSV-1, HSV-2, and HHV-8 are uncommon in HIV+ HNSCC; it is unlikely that these viruses have a promoting effect. MNTCG are significantly common in HIV+ HNSCC, but there is overlap in MNTCG counts with the control group and therefore this finding cannot be used as a biomarker of HIV infection.