Antiretroviral therapy has decreased HIV-related mortality. However, the incidence of diabetes as a co-morbidity is increasing as HIV-positive patients’ age. The purpose of this study was to assess the correlation between markers of HIV-infection and diabetes and to determine the proportion of patients achieving an A1c goal <7% according to specific antiretroviral therapy regimens and adherence. In this retrospective study, HIV-positive veterans with diabetes from 2007 to 2012 were identified. Patients were required to be on the same antiretroviral therapy and diabetes regimen for ≥3 months. In 56 patients, it was identified that for each unit increase in log₁₀ viral load, A1c increased 0.67 units (p = 0.0085). Only 38% of patients prescribed a protease inhibitor–based regimen vs. 56% of patients not on a protease inhibitor–based regimen achieved an A1c goal (p = 0.1864). Additionally, patients on an insulin-based regimen and patients that were less adherent were less likely to be at A1c goal (p = 0.018 and p = 0.0378, respectively). Patients with higher viral loads and patients that were less adherent to antiretroviral therapy were more likely to have a higher A1c demonstrating that poor adherence to antiretroviral therapy leads to poor control of both disease states.