Abstract Introduction The purpose of this study was to determine factors associated with seat belt usage among Emergency Medical Technicians (EMTs). Methods As part of biennial re-registration paperwork, nationally registered EMTs completed a survey on the safety and health risks facing Emergency Medical Services (EMS) providers. Respondents were asked to describe their seat belt use while in the front seats of an ambulance. They were categorized as “high” in seat belt use if it had been more than a year since they had not worn their seat belt or “low” in seat belt use if they had not worn their seat belt at least once within the past 12 months. A logistic regression model was fit to estimate the association between seat belt use, organizational seat belt policy, type of EMS organization worked for, EMT certification level, and the size of community where EMS work is performed. Results Of the 41,823 EMTs that re-registered in 2003, surveys were received from 29,575 (70.7%). A significant interaction between organizational seat belt policy and type of EMS organization was found to exist. Participants reporting no organizational seat belt policy had lower odds of seat belt usage when compared to individuals that do have a seat belt policy. Odds Ratios ranged from 0.20 (95% CI 0.10–0.40) for military organizations to 0.59 (95% CI 0.38–0.93) for private EMS organizations. Paramedics and those working in rural areas also had lower odds of seat belt use. Conclusion Several factors were found to be associated with seat belt usage among EMTs while in the front compartment of an ambulance. However, it appears that only one, organizational policy, is a modifiable characteristic.