Introduction: Over 1 million patients with head injuries (HIs) are seen every year at emergency departments (EDs) in North America, with over 90% being minor HIs. Over-utilization of computed tomography (CT) scans in these patients results in unnecessary exposure to radiation and increases health-care resource utilization. Using recommendations from the Choosing Wisely Campaign (CWC) and quality improvement (QI) methodology, we developed a local initiative targeting this issue. Our aim was to reduce the CT scan rate for patients presenting with HIs by 10% over a 6-month period at two academic EDs. This was considered both achievable and meaningful by our stakeholders. Methods: Baseline CT scan rates for patients with HIs were determined through a 10-month retrospective cohort review. We used stakeholder engagement and provider surveys to develop our driver diagram and PDSA cycles, which included: 1) Assessing and improving provider knowledge about the CWC recommendations; 2) Testing, refining and implementing a modified Canadian CT Head Rule checklist in the ED; 3) Developing and giving patients CWC-themed handouts pertaining to HI best practice; 4) Bimonthly reporting of CT scan rates to providers. Our primary outcome measure was the number of CT scans performed for patients with HIs. Process measures included the number of checklists completed and ED length of stay (LOS). Our balance measure was return ED visits within 72 hours. Results: Baseline rate of CT scans prior to our interventions was 47.9%. Our QI initiative resulted in a significant shift in the run chart of the weekly CT scan rates, associated with the second PDSA cycle cluster. We observed a 16% relative decrease in CT scans at 3 months (47.9% to 40.5%, P=0.005) and 10.4% at 8 months (47.9% to 43.1%, P=0.02). Non-sustained trends and shifts were seen in the run chart of median ED LOS for HI patients, but overall before-and-after median times were not significantly different (237min to 225min, P=0.18). 33% of total checklists were completed. 72-hr return visits did not change during the 8-month study period (4.0% to 4.16%, P=0.85). Conclusion: Our local QI initiative was successful in decreasing CT rates for patients presenting with a HI. The decrease in effect at 8 months suggests the need for continued feedback and reminders to ensure long-term sustainability. Other centres could use similar QI methods, as well as the materials we developed, to achieve similar results of improved evidence-based utilization of diagnostic tests.