Purpose of review There is a dual connection between violent behaviour and post-traumatic stress disorder. On one hand, exposure to violence leads to post-traumatic stress disorder symptoms, and on the other hand some of the symptoms of post-traumatic stress disorder are violent behaviour and aggression. In other words, violence creates post-traumatic stress disorder, and post-traumatic stress disorder contains violence. The frequency of violent behaviour as a background for the development of post-traumatic stress disorder is increasing. Exposure to violence, criminal and terrorist attacks, sexual (especially in early childhood) and physical abuse lead to anxiety, aggression, depression and post-traumatic stress disorder symptoms. Recent findings Different types of violence and their psychological and psychiatric consequences are now being researched to determine whether there are any differences in exposure to violence and its consequences with regard to age, sex, ethnicity, and sociodemographic characteristics. Apart from the individual and his/her family, the effects of violence on the wider community are being examined. In contrast, the well-described post-traumatic stress disorder, within the frame of increased alertness, can contain violence, aggression, anger, and impulsivity, which are a big problem for the patient and his/her family. These are the most common reasons for requesting psychiatric treatment. Summary Future research into violent behaviour and post-traumatic stress disorder will reveal the risk factors for this disorder, and try to explain what it is that, after exposing an individual to psychological trauma, leads to post-traumatic stress disorder. Possible protective factors and mechanisms to prevent the occurrence of post-traumatic stress disorder will be described.