BACKGROUND: Churches are important assets for the African American and Latino community. They can play a critical role in health promotion, especially in areas that are under-resourced and in which residents have limited access to health care. A better understanding of health promotion in churches is needed to support and maintain church collaborations and health initiatives that are integrated, data-driven and culturally appropriate. The purpose of this study is to identify churches’ facilitators and challenges to health promotion, and to contrast and compare Black and Latino churches of different sizes (