Background: Despite a push to implement evidence-based practices in behavioral healthcare, few studies have focused on the processes involved in this endeavor. This study describes the organizational transformation process at a large child and youth mental health service provider organization in Ontario, Canada. A detailed qualitative analysis of the change processes involved in shifting all service delivery to evidence-based practices examined process themes over time (4 years) and mapped these processes against the NIRN model of implementation. Methods/Design: This was a prospective single case study of process change in a child and youth mental health service provider organization using participant observation and verbatim field notes to capture elements of the change process over time (4 years). Results: Process themes from this real world change initiative did map onto the NIRN model of scaling up for organizational change. Emergent themes provide a rich, detailed description of the scaling up activities with respect to organizational change, building on the stages laid out by NIRN. Discussion: Findings have implications for the viable field use of the NIRN model for scaling up change and implementation of evidence-based practices in behavioural healthcare. Lessons learned provide greater definition of issues related to EBP change implementation that can assist other organizations. © Common Ground, Melanie Barwick, Melissa Kimber, Gwendolyn Fearing, All Rights Reserved.