Summary Although our understanding of workplace stressors has grown across the past 30 years, this research has generally ignored traumatic workplace stressors. This is a serious omission, given that many occupations (e.g., firefighters, emergency medical technicians, and police) are frequently exposed to traumatic stressors. As such, the first purpose of the current study was to examine the impact of exposure to traumatic stressors in firefighters. Post‐traumatic stress disorder (PTSD), burnout, and absenteeism were investigated as cognitive, affective, and behavioral outcomes. Additionally, we sought to investigate coping humor as a mechanism for dealing with traumatic stressors. We frame these expectations by discussing humor from a transactional theory of emotion/coping perspective, as well as through humor's social bonding feature and its ability to combat the physiological impact of stressors. We surveyed 179 firefighters at two time points on relevant variables, with dependent variables collected at Time 2. The results indicated that traumatic events significantly predicted burnout, PTSD, and absenteeism and that coping humor buffered this relationship for burnout and PTSD. We discuss the implications of these findings and call for more research investigating occupations in which traumatic stressors are a concern, as well as for more integration of humor into the workplace literature. Copyright © 2013 John Wiley & Sons, Ltd.