© 2019 - IOS Press and the authors. All rights reserved. BACKGROUND: Firefighters have high rates of exposures to critical events that contribute to physical and mental stress, resulting in high rates of injury and work-injury compensation claims. OBJECTIVE: To determine the prevalence of critical incidents in firefighters from a single fire service, and whether the number of critical events varied based on age, gender, years of service and/or rank. METHODS: We recruited 300 full-time firefighters. Firefighters were asked to complete a self-report Critical Incident Inventory survey that included questions on exposure to critical events during firefighting duties, with a time reference point of the past two months. RESULTS: Among the 293 firefighters, 252 (85%) indicated exposure to some type of critical incident. More specifically, 187 (64%) reported a respond to incident involving one or two deaths, 155 (53%) indicated a direct exposure to blood and body fluids, and 98 (33%) reported a response to an incident involving multiple serious injuries. Age, gender, years of service and rank accounted for only 1% of the variance in the number of critical incidents among firefighters. CONCLUSIONS: In this study, 85% of firefighters had been exposed to some type of critical incident in the previous 2-months and this did not vary by age, gender, years of service and/or rank.