Although violence is increasing in most workplaces, it has become a significant problem in health care professions. Not only has the number of incidents increased but also the severity of the impact has caused profound traumatic effects on the primary, secondary and tertiary victims. More health care professionals than ever are suffering from symptoms of post-traumatic stress disorder. Addressing the problem of violence in the workplace has been exacerbated by a lack of a clear definition of what constitutes aggression and violence. As a result, some administrators have been slow to commit resources to prevent further incidents and mitigate the impact. This article describes the magnitude of the problem from both an academic research and an operational perspective. A definition is presented as an initial step towards standardizing the research, and establishing an appropriate baseline upon which intervention policies and procedures can be created. This benchmark will also help to encourage empirical research into aggression and violence in health care professions and other professions. Further research needs to be conducted to create a comprehensive instrument that can more accurately measure the range of incidents and the severity of the impact.