Background: Community engagement is critical to the acceleration of evidence-based interventions into community settings. Harnessing the knowledge and opinions of community leaders increases the likelihood of successful implementation, scale up, and sustainment of evidence-based interventions. Faith in Action (Fe en Acción) is an evidence-based promotora-led physical activity program designed to increase moderate-to-vigorous physical activity among churchgoing Latina women.Methods: We conducted in-depth interviews using a semi-structured interview guide based on the Consolidated Framework for Implementation Research (CFIR) at various Catholic and Protestant churches with large Latino membership in San Diego County, California to explore barriers and facilitators to implementation of Faith in Action and identify promising implementation strategies for program scale-up and dissemination. We interviewed 22 pastors and church staff and analyzed transcripts using an iterative-deductive team approach. Results: Pastors and church staff described barriers and facilitators to implementation within three domains of CFIR: characteristics of individuals (lack of self-efficacy for and knowledge of physical activity; influence on churchgoers’ behaviors), inner setting (church culture and norms, alignment with mission and values, competing priorities, lack of resources), and outer setting (need for buy-in from senior leadership). From the interviews, we identified four promising implementation strategies for the scale-up of faith-based health promotion programs: 1) health behavior change training for pastors and staff; 2) tailored messaging; 3) developing community collaborations; and 4) gaining denominational support.Conclusions: While churches can serve as valuable partners in health promotion, specific barriers and facilitators to implementation must be recognized and understood. Addressing these barriers through targeted implementation strategies at the adopter and organizational level can facilitate improved program implementation and lead the way for scale-up and dissemination.