Research suggests that violence has entered the medical setting to a remarkable degree, causing medical professionals to be at the highest risk for becoming the victims of assaults and violent acts. This article reviews general theories of aggression and research on these theories, and uses them to assess risk factors in patients with chronic pain. There are data to suggest that pain may increase the risk of aggressiveness in some patients. However, it may decrease the risk in others paradoxically. The research available underscores the need for evaluating patients with pain for the risk of violent or aggressive behavior; specific recommendations are made in this regard.