As well as being a violation of human rights, violence against women can be regarded as an 'emerging health problem' of the late twentieth century not because it is new, but because its prevalence and role in the aetiology of ill health has only recently been widely recognized. In this paper we discuss the epidemiology and health impact of violence against women, drawing particularly on data from research in South Africa. Here the prevalence of abuse is between 20% and 30%, which is in keeping with estimates for other countries and research has shown that 1% of women are raped each year. Gender-based violence is an appreciable cause of mortality from homicide and suicide. It is also associated with a range of other health problems, particularly injuries, HIV and sexually transmitted diseases, pregnancy complications and mental health problems. Available estimates suggest that it is associated with considerable costs to the health sector. Roles for the health sector in breaking cycles of abuse are increasingly being recognized and there is a need for appropriate interventions, based on screening, homicide and suicide risk assessment, documentation, information giving and referral to be implemented more widely in health facilities.