Few rural minorities participate in HIV clinical trials. Mobile health units (MHUs) may be one strategy to increase participation. We explored community perceptions of MHU acceptability to increase clinical trial participation for rural minorities living with HIV/AIDS. We conducted 11 focus groups (service providers and community leaders) and 35 interviews (people living with HIV/AIDS). Responses were analyzed using constant comparative and content analysis techniques. Acceptable MHU use included maintaining accessibility and confidentiality while establishing credibility, community ownership and control. Under these conditions, MHUs can service rural locations and overcome geographic barriers to reaching major medical centers for clinical trials.