Background: HIV prevalence among people who inject drugs (PWID) in Kenya is estimated to be 18% compared to 4.5% in the general population. Studies from high-income countries have demonstrated that methadone use is associated with increased uptake of antiretroviral therapy (ART) and higher rates of viral suppression among PWID with HIV. However, it is unclear whether methadone use has the same effect among African PWID living with HIV.