Background: Despite a push to implement evidence-based practices in health and mental health, few studies have focused on the processes involved in this endeavor. This paper describes an organizational transformation process being undertaken at a large child and youth mental health service provider organization in Ontario, Canada. Utilizing existing knowledge about successful implementation of evidence based practices in social services, this geographically dispersed, large, non-profit organization is undergoing a multi-year change of its service provision and culture. This study is designed to provide a detailed description of the processes involved in implementing evidence-based practices and to test the NIRN model of implementation. Methods/Design: This is a prospective single case study of process change in a single child and youth mental health service provider organization using mixed methods to capture elements of the change process over time (4 years). Data collection will involve field notes of selected meeting groups, interviews with randomly selected employees involved in the change process, annual questionnaires of all staff, and tracking of meetings, milestones, and goals. The extent to which the organization demonstrates qualities characteristic of a learning organization will be captured with the Organizational Learning Survey. Discussion: This study will provide a detailed description of the change processes related to the implementation of evidence-based practices in a child and youth mental health provider organization. The approach will also test the NIRN implementation framework in a real world setting. Findings will significantly enhance the knowledge of implementation in the field and provide other organizations with a tested model and implementation framework. © Common Ground, Jacquie Brown, Jane Rounthwaite, Melanie Barwick, All Rights Reserved.