Objective: The aim of the study was to describe the epidemiology of trauma in adult patients attended by ambulance paramedics in Perth, Western Australia. Methods: A retrospective cohort study of trauma patients aged ≥16 years attended by St John Ambulance Western Australia (SJA-WA) paramedics in greater metropolitan Perth between 2013 and 2016 using the SJA-WA database and WA death data. Incidence and 30 day mortality rates were calculated. Patients who died prehospital (immediate deaths), on the day of injury (early deaths), within 30 days (late deaths) and those who survived longer than 30 days (survivors) were compared for age, sex, mechanism of injury and acuity level. Prehospital interventions were also reported. Results: Overall, 97 724 cases were included. A statistically significant increase in the incidence rate occurred over the study period (from 1466 to 1623 per 100 000 population year P ≤ 0.001). There were 2183 deaths within 30 days (n = 2183/97 724, 2.2%). Motor vehicle accidents were responsible for most immediate and early deaths (n = 98/203, 48.3% and n = 72/156, 46.2%, respectively). The majority of transported patients were low acuity (acuity levels 3 to 5, n = 60 594/79 887, 75.8%) and high-acuity patients accounted for 2.7% (n = 2176/79 997). Analgesia administration was the most frequently performed intervention (n = 32 333/80 643, 40.1%), followed by insertion of intravenous catheters (n = 25 060/80 643, 31.1%). Advanced life support interventions such as endotracheal intubation were performed in <1% of patients. Conclusion: The trauma incidence rate increased over time and the majority of patients had low-acuity injuries. Focusing research, training and resources solely on high-acuity patients will not cater for the needs of the majority of patients.