Oropharyngeal cancer (OPSCC) is an increasing public health problem worldwide. Recent studies indicate that human papillomavirus (HPV) infection is the main driving force of this new epidemic. We believe that HPV-positive OPSCC is more prevalent compared HPV-negative OPSCC among HIV patients and that HIV-infected patients receiving appropriate antiretroviral therapy (ART) have worse outcomes compared to HIV non-infected patients after controlling for HPV. To develop the preliminary data required to assess these critical questions, we will conduct a cohort study on all patients receiving treatment for OPSCC in Botswana in order to determine the relative contribution of HPV to the overall burden of OPSCC in the country. We will also determine the differences in treatment tolerability between HIV positive and negative patients and evaluate predictors of poor tolerability and local control (e.g. ART, CD4 count, total treatment time, stage, smoking history and HPV-subtype) in both groups.