A needs assessment funded by the Center of Substance Abuse Prevention was conducted in 2005-2006 to determine the HIV/AIDS, substance abuse, and hepatitis prevention needs of Native Americans living in Baltimore, Maryland. We used a community-based participatory approach to gain an in-depth understanding of local Native American health service needs. Community stakeholders and key informants embedded in the local Native American population were consulted at each stage of the research planning process. Two complementary methodologies (focus groups and surveys) produced a holistic assessment of the population's needs, risks, and strengths and uncovered the social and cultural contexts in which health risk behaviors unfold. The use of these methods within a participatory framework produced a more complete portrait of the service needs of the Native American population in Baltimore. Findings from this study support the necessity for future HIV/AIDS, substance abuse, and hepatitis prevention programming for urban Native Americans.