INTRODUCTION: We aimed to assess the impact of introduction of a dedicated trauma surgical unit (TSU) on CT utilisation for polytrauma in the Emergency Department (ED). METHODS: Single centre retrospective cohort study comparing adult patients undergoing CT for polytrauma following TSU introduction (Intervention group, n = 617) to a historical Baseline group (n = 257) over a matched time period. Patient impact, including initial clinical assessment, injuries, radiation exposure, incidental findings, ED disposition, and impact on radiology services were compared with Mann-Whitney and Fisher's exact tests. RESULTS: Intervention patients were more likely to be examined by ED physicians (96.7% vs. 91.1%, p = 0.001) prior to CT. There was greater documented clinical suspicion for chest and abdominal injuries, with increased WBCT utilisation for Intervention (Baseline 17.1% vs. 47.8%, p <
0.05), with no significant increase in positive scans by region. More CT chest (Intervention 38.4% vs. Baseline 14.8%, p <
0.05), CT abdomen (42.6% vs. 12.6%, p <
0.005) and CT pelvis (46.1% vs. 16%, p <
0.001) was performed even with low documented clinical suspicion, with no significant increase in positive findings. The intervention group returned for more additional scans (12.48% vs. Baseline 5.45%), had more incidental findings (23.66% vs. 15.18%), and were more likely to be admitted for observation (21.7% vs. 14%), all p <
0.05. Time to scan and total CT reporting time were significantly longer for Intervention. CONCLUSION: Introduction of a TSU was associated in a shift towards increased CT utilisation, with no increase in scan yield, increased incidental findings and impacts on Radiology workflow.