Community collaboration in research may lead to better methods, results, and dissemination of interventions. Little systematic research has examined specific factors that influence community-based organizations (CBOs) to collaborate in public health research. There is an urgent need to advance knowledge on this topic so that together, researchers and CBOs can minimize barriers to collaboration. This study advances a CBO-focused characterization of collaboration in HIV-prevention research. By focusing on the perspectives of 20 key informants in 10 HIV-prevention CBOs, qualitative data revealed factors that influenced their collaborations in four domains: (a) Researchers' Characteristics (expertise, availability), (b) Collaborative Research Characteristics (ought to improve services and CBO infrastructure); (c) Community Partner--Researcher Relationships (resolving social and professional issues); and (d) Barriers to HIV-Prevention Research Collaboration (cultural and social disconnect between CBO and academia). To reduce barriers, researchers ought to enhance motivators that facilitate collaboration. To use the advantages of community-based research, prevention scientists and policy makers ought to embrace CBOs' characterization of what makes health research genuinely collaborative. (Contains 1 table.)