IntroductionAddressing clinical variation in elective surgery is challenging. A key issue is how to gain consensus between largely autonomous clinicians. Understanding how the consensus process works to develop and implement perioperative pathways and the impact of these pathways on reducing clinical variation can provide important insights into the effectiveness of the consensus process. The primary objective of this study is to understand the implementation of an organisationally supported, consensus approach to implement perioperative care pathways in a private healthcare facility and to determine its impact.MethodsA mixed-methods Effectiveness-Implementation Hybrid (type III) pre–post study will be conducted in one Australian private hospital. Five new consensus-based perioperative care pathways will be developed and implemented for specific patient cohorts: spinal surgery, radical prostatectomy, cardiac surgery, bariatric surgery and total hip and knee replacement. The individual components of these pathways will be confirmed as part of a consensus-building approach and will follow a four-stage implementation process using the Exploration, Preparation, Implementation and Sustainment framework. The process of implementation, as well as barriers and facilitators, will be evaluated through semistructured interviews and focus groups with key clinical and non-clinical staff, and participant observation. We anticipate completing 30 interviews and 15–20 meeting observations. Administrative and clinical end-points for at least 152 participants will be analysed to assess the effectiveness of the pathways.Ethics and disseminationThis study received ethical approval from Macquarie University Human Research Ethics Medical Sciences Committee (Reference No: 520221219542374). The findings of this study will be disseminated through peer-reviewed publications, conference presentations and reports for key stakeholders.