Emergency situations are very specific from all points of view, they put the individual(s) in difficult and unusual conditions, very often in dangerous ones. These conditions require a quick (re)action of people in order to avoid the unpleasant and unexpected consequences. Ordinary people react in their manner of dealing with stressful situations, i.e. according to their coping strategies. Sometimes such situations could be traumatic and generate the appearance of post-traumatic stress-disorder. First responders, people that meet emergency and traumatic situations everyday are people that should deal with stress always. And one of our main purposes is to study the coping mechanisms of first responders – firefighters, police officers, security staff, paramedics etc. – namely we are interested in the presence of avoidance reaction, i.e. self-protective behavior. According to some researches the first responders are characterized by higher frequency of PTSD, even if the stressful situations are their daily reality, and they should learn how to deal with them, how to be emotionally and psychologically strong. In this paper we analyzed the specialized literature regarding PTSD in emergency situations. Even if the term was introduced officially in 1980, it has a very intense development from theoretical and practical points of view. Nowadays researchers are focusing on finding best ways of its treatment (different therapeutic approaches, medical treatment, the importance of social support), its peculiarities depending on trauma type, its peculiarities depending the category of people exposed to trauma, its effects on psychological and physical functioning of people with PTSD, the improvement of PTSD diagnostic methods, the efficient methods of reducing the symptoms of PTSD, the predictors of PTSD symptoms, risk-factors for PTSD etc.