Aggressive violence has been described as the greatest problem and the most frequent reason for referrals in child and adolescent psychiatry. In this country we have only partially emerged from an epidemic of violence that was really an epidemic of youth violence. Thus it is hardly surprising that psychiatrists are being asked more and more frequently whether psychiatric medications might help to diminish the toll from this behavioral plague. Medications are useful and appropriate for only a small minority of the people who commit serious violence. Even when they are indicated, they can never be the sole treatment modality, but should be supplemented by psychological and social therapies. When the violence is a byproduct or symptom of an underlying mental illness, treating that illness is generally the most effective method of preventing future violence on a long-term basis. However, most violence is not committed by those who are mentally ill, and most of the mentally ill never commit a serious act of violence. That is why many attempts have been made to discover whether there are drugs that diminish the symptom, violence, even when there is no underlying mental illness for which drugs would normally be prescribed. In fact there are several, and their indications and use are reviewed here. Different principles govern the acute short-term emergency treatment of a violent crisis and the long-term treatment of those who are chronically and repetitively violent, and these differences are also summarized here.