Aggression is a deliberate series of actions that lead to harm, injury, or destruction of another organism, and is the most common factor promoting violent crimes. Beyond being the immediate cause of physical injury, aggressive behavior also produces profound long term emotional disabilities in its victims. When outburst of aggression is comorbid with DSM-IV-defined neuropsychiatric disorders, the offenders are usually given psychiatric care; however, when they appear normal or healthy, their most likely fate is punishment by the law. This punitive approach often increases aggression, thereby promoting the propensity for violent crimes. Antipsychotics are the drugs commonly used for treatment of aggression and violent outbursts. However, the uses of these drugs have serious side effects of catalepsy or impairment of sensorimotor performance. They also affect the defense or flight capabilities of organisms, which further limit their usefulness in aggression. Thus, there is a critical need to search for agents that can selectively reduce aggression without affecting other behaviors or causing any serious unwanted side effects. This review focuses on the types, neurochemical bases, and animal models of aggression, with a comprehensive appraisal of the pharmacological approach to the treatment of the disorder.