Aim: To describe the multi-level strategies for and impact on patient outcomes and nursing practice of implementing Best Practice Guidelines (BPG) at the McGill University Health Centre. Background: This 3-year initiative, part of an inter-disciplinary effort led by the nursing department, is promoting patient safety and quality of care using multiple interventions at multiple levels to implement BPGs related to prevention of pressure ulcers and falls and pain management. We designed organization-level activities to promote leadership support for organizational change, organization-wide awareness of BPGs and corporate level support for required resources. Organizational strategies consist of the creation of an infrastructure that includes three inter-disciplinary Task Forces, project leaders, financial support for learning activities and organizational experts in facilitating guideline implementation. At the departmental level, Task Forces have formulated specific recommendations for action such as interactive, context- and guideline-specific learning and support activities that include a Train-the-Trainer model. At the unit level, staff and unit leaders work to adapt the plans and learning or support activities to their context, select unit-based champions/facilitators and decide on specific targets and strategies. Method: We use a non-equivalent control group pre-test-post-test design and triangulate methods and data sources to evaluate outcomes. In addition to measures of organizational context (patient safety, organizational support for BPG implementation), we are assessing, on implementation and comparison units, nursing practice (documentation of recommended practices) and patient outcomes (pressure ulcer, pain level or fall incidence) at base-line and 6 months following 8 weeks of unit-based implementation activities. Results: 32 units (18 implementation and 14 comparison units) participated in the study (N=734 nurses and 898 patients at baseline).  Analysis examines between group differences over time in the patient assessments, chart review and survey results.   Conclusion: Achieving safer care through the implementation Best Practice Guidelines recommendations requires an organizational wide effort.