ABSTRACT: BACKGROUND: The recent development and publication of evidence-based clinical practice guidelines (CPGs) for acute low back pain (LBP) has resulted in evidence-based recommendations that, if implemented, have the potential to improve the quality and safety of care for acute LBP. While a strategy has been specified for dissemination of the CPG for acute LBP in Australia, there is no accompanying plan for active implementation. Evidence regarding the cost-effectiveness of active implementation of CPGs for acute LBP is sparse. The IMPLEMENT study will consider the incremental benefits and costs of progressing beyond development and dissemination to implementation. METHODS/DESIGN: Cost-effectiveness and cost-utility analyses alongside the IMPLEMENT cluster randomised controlled trial (CRCT) from a societal perspective to quantify the additional costs (savings) and health gains associated with a targeted implementation strategy as compared with access to the CPG via dissemination only. DISCUSSION: The protocol provided here registers our intent to conduct an economic evaluation alongside the IMPLEMENT study, facilitates peer-review of proposed methods and provides a transparent statement of planned analyses. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN012606000098538.