International experience of carrying out research on violence against women among women who may have experienced such violence and among men who may have been violent has raised a number of ethical issues, which appear in sharp focus. This paper is based on the collective experiences derived from involvement in three large gender-based violence surveys in South Africa and one in Zimbabwe. These are broadly concerned with the safety of researchers and research subjects from violence arising because of the research project, risks of traumatisation of both respondents and researchers as violent experiences are recounted; impact of work on violence as an issue in researchers' own relationships; risks of under-reporting the extent of violence experienced or perpetrated; and the need for research efforts to be followed up in ways beneficial to women experiencing violence, such as increased support, public information, and law and policy changes. This paper discusses how these issues have pertained and been addressed in research on gender-based violence in Southern Africa and consider lessons for this and other sensitive areas of reproductive and sexual health research.