Children who witness marital abuse constitute a kind of population at risk that is still all too often underestimated in France. Nevertheless, the extent and seriousness of the violence involved here should alert us to the present and future repercussions on such children. Research in North America concentrates mostly on visible symptoms and the risks of transgenerational repetition of violent behavior, without investigating the psychological mechanisms in play. But these mechanisms may partly explain why the violence of marital abuse is so difficult to eradicate from our societies. Indeed, it persists in spite of systems of treatment and preventive measures. We thus seek to elucidate what is at stake psychically for the child witness of violence and his mother, in order to explain and try to prevent these phenomena of repetition. We discuss two clinical illustrations that reveal the fundamental fragility of these childrens’ “skin-ego” and the difficulties faced by their mothers, so as to show how necessary it is to support the mother-child bond.