Aggressive and violent behaviour has always been considered, in popular belief, a major characteristic of mental illness. This wrong assumption has contributed greatly in the stigmatization of mentally ill individuals. However, violence and aggression apart from being human behaviours are symptoms of many psychiatric disorders. This presentation reviews the psychiatric diagnoses that include violence or aggression as one of the prerequisite symptoms for the diagnosis. These nosological entities include schizophrenia, bipolar disorders, mental retardation, acute confusional states and dementia as well as certain personality disorders. Detailed psychopathological descriptions of violence and aggressive behaviour will further the classification and definition of this destructive and damaging behaviour and increase our understatnding of the association between the symptom and the psychiatric disorder.