Faith-based interventions show promise for reducing health disparities among ethnic minority populations. However, churches vary significantly in their readiness and willingness to support these programs. Semistructured interviews were conducted with priests, other church leaders, and lay health advisors in churches implementing a physical activity intervention targeting Latinas. Implementation effectiveness was operationalized as average 6-month participation rates in physical activity classes at each church. Factors facilitating implementation include church leader support and strength of parishioners' connection to the church. Accounting for these church-level factors may be critical in determining church readiness to participate in health promotion activities.