Background: Co-signaling molecules PD-L1, B7-H3, and PD-1 play a key role in CA immunology. Their expression has not been characterized for AD tumors in patients with HIV. Methods: We reviewed 30 cases of archived tissue from HIV-infected patients with head and neck (H&N) (n = 17) and lung (n = 13) CA from 2001-2011. Baseline demographics, CD4 count, HIV RNA viral load (VL) and antiretroviral therapy (ART) at diagnosis were collected. Immunostained tumor sections were analyzed for percent of tumor cells expressing PD-L1 and B7-H3 (Abcam), and percent of tumor infiltrating lymphocytes (TIL) expressing PD-1 (Abcam). Positive expression was defined as staining > 5% of tumor cells. Correlation between CD4 or VL with biomarkers was performed using Spearman’s rank correlation, Rs. Results: Of H&N CA, 9 (52.9%) were positive for PD-L1 (mean % expression 14.7, 95%CI 3.9-25.5), 16 (94.1%) were positive for B7-H3 (mean % expression 49.4, 95%CI 35.4-63.4), and 14 (82.4%) had TIL that were positive for PD-1 (mean % expression 44.7, 95%CI 29.1-60.3). In lung CA, 3 (23.1%) were positive for PD-L1 (mean % expression 20, 95%CI -0.7-40.7), 12 (92.3%) were positive for B7-H3 (mean % expression 66.2, 95%CI 48.2-84.2), and 9 (69.2%) had TIL that were positive for PD-1 (mean % expression 25.4, 95%CI 9.6-41.2). All 3 lung tumors that stained positive for PD-L1 had high levels of PD-L1 expression (80-90%). In lung CA, CD4 count positively correlated with %PD-L1 (Rs = 0.61, p = 0.05). In H&N CA, VL positively correlated with %PD-1 expression in TIL (Rs = 0.73, p = 0.003). Conclusions: AD tumors in patients with HIV express PD-L1 and B7-H3, and have TIL that express PD-1. Our data suggests that patients with AD CA and HIV have similar rates of biomarker expression compared to published rates in non-HIV patients. Our findings support inclusion of these patients in future immunotherapy trials.