Violence is one of the most serious problems that society, and the public health sector in particular, has to deal with today. This article begins with a discussion of the concept of violence itself, bringing out its historical and cultural dimensions and emphasizing its essential relationship to the exercise of force in the interest of power under conditions of inequality. Violence must be seen as a process that includes its origins, the conditions that allow it to happen, its different forms of expression, and its individual and collective consequences. The violence–health relationship is seen as having different levels: violence threatens or denies not only health but the entire vital human process. The author analyzes the different forms of violence: violence that impairs health (torture, disappearances, rape, child abuse, elderly abuse) and violence that kills (suicide, homicide, war). Recent data show that the problem is on the increase and pervades everyday life. The author then examines the mechanisms by which violence impinges on health care institutions, especially the health services, training institutions, and agencies responsible for orienting and financing the sector. Finally, the health sector is revealed as not only a victim or patient of violence, but, unfortunately, sometimes an agent of violence, which means that changes are needed in approaches, attitudes, and behavior.