A psychosocial model is presented that suggests sports fan violence results from a series of intrapersonal, environmental, and social conditions. Given appropriate cues and direction at competitive sports events, these conditions predispose fans to act in a violent way. By understanding interrelationships among these conditions, it may be possible to assess their importance at sporting events and the likelihood of fan violence developing. If potential violence can be predicted, proactive steps may be taken in accordance with the presenting factors. Appropriate proactive steps may include banning alcohol and increasing security between opposing fan groups. A historical overview of sports-related violence is presented, and theories of crowd and collective behavior are discussed. 49 references and 1 table