Violence is a manifestation of aggression. Aggressive behavior is a personality trait that comprises hostile, threatening and physical violence towards persons and objects. Aggression is a complex behavioral phenotype with a major genetic component. Hence it is reasonable that neural circuitries that affect emotional states like the central serotonergic, dopaminergic and noradrenergic systems also affect the predisposition towards aggressive and antisocial behaviors. Large number of candidate gene studies for aggression has been conducted worldwide. Successful identification of associations between genetic markers and aggression would contribute to understanding the neurobiology of antisocial behavior and potentially provide useful tools for risk prediction and therapeutic targets for high-risk groups of offenders and psychiatric patients.