[Violence and health: theoretical, methodological, and ethical contributions from studies on violence against women]

This article discusses theoretical, methodological, and ethical aspects pertaining to violence against women as both a form of gender violence and a public health issue. The text provides epistemological reflections based on daily research experience with qualitative and quantitative, population-based, and service-user studies that address both women and men. Violence is defined as a complex and sensitive theme of a medical and social nature in terms of its theoretical-methodological approach, pointing to interdisciplinarity as the reference for its construction as an object of health. The article discusses the difficulties in linking the various sciences, methodologies, and theoretical perspectives. It also highlights the special dynamic between visible and invisible violence, with implications for research design, particularly for demarcating the object of study, a relevant issue given the technological needs of health intervention. These specificities of violence raise further ethical issues for the production of knowledge, and there is a need for special care as part of methodological quality in the research. Research ethics is also responsible for the scientificity of the resulting data. Situations stemming from specific studies are used to illustrate the article's commentary.