The three main sources of information about domestic violence are official records, social surveys, and clinical or program data. The available data indicate that dating and courtship violence rates vary from 10 percent to 67 percent of all couples; 27 percent of couples report severe violence during courtship. Surveys variously report prevalence rates of 10-30 percent of households. Women are more likely than men to be injured in partner violence; partner violence may be the most frequent source of injury to women as well as the single most common cause of injuries for which women seek emergency medical attention. Theories range from ecological and cultural explanations to individual-level explanations. Marital violence is likely to be a reciprocal process involving arousal, personality, situational, and cultural factors. However, little theoretical rational exists for handling domestic violence differently from other forms of violence; the contemporary focus is on violence generally and not on specific types of victims. Police, health care providers, and social service agencies are increasingly working together to address domestic violence. However, data are lacking regarding the relative effectiveness of various responses. Therefore, current innovations should not become a new orthodoxy that precludes the introduction of new and perhaps more effective methods to help victims of domestic violence. Notes and approximately 150 references