Violence in the emergency department is a common concern. However, most aspects of this problem remain unstudied because no organization or government agency tracks such data and no regulatory or administrative guidelines adequately address its management. We surveyed 170 US teaching hospital ED medical directors with respect to violence and security issues and received responses from 127 (74.7%). Among other findings, 41 institutions report at least one verbal threat each day, and 23 report at least one threat with a weapon each month. Four-point physical restraint is used by 125 of the 127 facilities. Personnel in 32 of these facilities restrain at least one patient each day. Seventeen institutions report having significantly injured a patient during restraint in the last five years, resulting in one death. Twenty institutions report involvement with litigation with respect to restraint. Only 51 institutions provide ED nurses with formal training in recognition and management of aggression and violence, and only 79 institutions have security personnel present in the ED 24 hours a day. A sizable number of facilities receiving frequent threats and batteries are not among those with 24-hour-a-day security personnel. A preventative, risk-management approach that addresses environmental factors, training policies, restraint, security arrangements, and legal precedents is suggested.