In this article Gerald Campano, María Paula Ghiso, and Bethany J. Welch explore the role of ethical and professional norms in community-based research, especially in fostering trust within contexts of cultural diversity, systemic inequity, and power asymmetry. The authors present and describe a set of guidelines for community-based research that were developed through collaborative inquiry into an ongoing research partnership with a multilingual and multiethnic Catholic parish and its school and community center. The norms emerged from investigating the reciprocal and recursive relationship between the authors' roles as scholars and practitioners. Campano, Ghiso, and Welch use this illustrative case to provide an example of how professional norms were conceptualized and enacted in an effort to nurture long-term research relationships across institutional and social boundaries. As research from university-community partnerships continues to grow, the authors emphasize the need to make explicit and to consider with greater specificity the ethical dimensions of our research.