This article analyzes the identity-building process for community-based health workers in the context of their role in the Health Family Program team and their interaction with the residents of communities where they work. Based on this analysis we specifically emphasize conflicts of interpretation, power relationships between both sides of identity-building for community-based health workers from three perspectives: that included in the official training of these workers, that produced by workers concerning themselves, and that transmitted by the community. The fact that community-based health workers live the reality of health practices in the neighborhoods where they live and work and are trained with biomedical references makes them actors that convey both the contradictions and the possibility for a deep dialogue between these two forms of knowledge and practice.