The review summarizes current scientific knowledge on the effects of railway critical incidents on railway workers and the associated risk and protective factors. Diagnosable traumatic reactions sometimes occur after a serious incident. However, the most frequent effects are long-term impairments that do not meet diagnostic criteria but can still profoundly affect people’s lives. Risk factors that can increase the negative effects of incidents include characteristics of the employee, coping mechanisms, the type of incident, and the support and care received. Prevention and intervention programs should consider the diversity of reactions to develop relevant support programs.