Understanding staff concerns about a systemic change effort allows leadership teams to better anticipate and address staff needs for professional development and support. In this study, staff concerns in nine schools planning for or implementing School-Wide Positive Behavior Interventions and Supports (SWPBIS) were explored using the Concerns-Based Adoption Model (CBAM). The concerns of staff were coded and aggregated to generate group concern profiles. Results revealed that planning and implementing staff most frequently reported task-related concerns associated with managing, organizing, and implementing SWPBIS. More staff in planning schools were unaware of SWPBIS, while more staff in implementing schools were concerned with the impact of SWPBIS on students. Across all schools, the majority of staff reported their support for SWPBIS implementation, but they were concerned about the support and implementation of their colleagues. Analysis of concerns in this manner can help teams to understand the nature of staff concerns in their school and better target areas of professional development at the universal, targeted, and individual level of SWPBIS. Additional implications for practice are discussed.