Few rigorously tested primary prevention programs have been developed to prevent HIV infection among immigrant communities in the United States. This is in part because of the lack of culturally specific behavioral theories that can inform HIV prevention for immigrant communities in the United States. This article aims to develop such theories for a population--Asian/Pacific Islanders (A/PIs) immigrant communities--who have been overlooked in theory development and program evaluation. Frontline community-based organization (CBO) peer educators, an underutilized source of expertise regarding cultural factors specific to HIV infection among A/PI communities, are the sample of study Asian/Pacific Islander peer educators working at an urban AIDS service organization devoted to health promotion for this population; (N = 35). They were interviewed to examine (1) detailed narratives describing instances of behavior change and (2) culturally anchored theories of behavior change which the narratives imply. Theories of the influence of positive cultural symbols on the taboo of HIV/AIDS, moderators of the effectiveness of social network influences on behavior change, and setting- and community-level processes predicting HIV risk behavior were implicit in the peer educators' narratives. Implications for future research, methodology and prevention practice are discussed.