Questions: What proportion of people who are managed by a primary-contact physiotherapy service in an emergency department experience adverse events? For people presenting to the emergency department with minor trauma, does the length of stay differ between those managed by the physiotherapy service and those managed by medical staff? For people presenting to the emergency department with minor trauma, is diagnostic imaging ordered as often by the physiotherapy service as it is by medical staff? Design: Prospective, observational, cohort study. Participants: A consecutive sample of 1320 people presenting to an emergency department and managed by the physiotherapy service was analysed. Where possible, these patients were matched by diagnostic codes - typically for minor trauma including closed fractures of the periphery - to patients who were managed by medical staff in order to generate two matched cohorts for comparison. Outcome measures: The outcome measures were adverse events among the patients managed by the physiotherapy service, the average length of stay of each cohort in the emergency department, and the proportion of patients in each cohort who underwent diagnostic imaging studies, including plain radiographs, computerised tomographic scans, and ultrasound imaging studies. Results: No misdiagnoses or adverse events were identified for any patient managed by the physiotherapy service. The patients managed by the physiotherapy service had a significantly reduced length of stay (mean difference 83. minutes, 95% CI 75 to 91) and significantly fewer requests for each type of imaging than the matched patients managed by medical staff. Conclusion: Primary-contact physiotherapists can manage a minor trauma caseload in the emergency department without adverse events. A physiotherapy service in the emergency department may result in a reduced length of stay and fewer requests for imaging. However, potential confounding of the results for length of stay and imaging must be recognised because matching diagnostic codes may not ensure completely equivalent cohorts. [Sutton M, Govier A, Prince S, Morphett M (2015) Primary-contact physiotherapists manage a minor trauma caseload in the emergency department without misdiagnoses or adverse events: an observational study.