State mental health authorities have a leadership role in implementing evidence-based practices (EBPs), but few instruments are available to assess the impact of this role. We describe the development of the State Mental Health Authority Yardstick (SHAY), a behaviorally anchored instrument designed to assess state-level facilitating conditions associated with successful implementation of EBPs in community mental health centers. The SHAY assesses the SMHA role in seven domains: Planning, Financing, Training, Leadership, Policies and Regulations, Quality Improvement, and Stakeholders. Preliminary evidence from the National Evidence-Based Practices Project partially supports the construct and criterion-oriented validity of this instrument for rating state-level activities supporting or blocking the implementation of evidence-based practices.