The purpose of this study was to identify the critical behaviors of supervisors for the successful implementation of evidence-based practice in adult mental health. Experts who work with supervisors to support implementation in three evidence-based practices were surveyed. The three evidence-based practices included Assertive Community Treatment, Integrated Dual Diagnosis Treatment, and Supported Employment. There was substantial agreement among experts as to the importance of supervisory behaviors in the areas of facilitating team meetings, building and enhancing staff skills, monitoring and using outcomes, and continuous quality improvement activities.