Munchausen syndrome by proxy is a form of child abuse presenting as a disease produced or simulated by a parent, the mother in most cases. Its diagnosis is uneasy because of its miscellaneous and unusual clinical presentation and of the misleading apparently normal attitude of the parents. Physicians may participate in the abuse by insistently looking for diagnostic and therapeutic measures, therefore contributing to the significant mortality of the syndrome. It is therefore important that physicians consider Munchausen syndrome in any ambiguous situation in order to protect the child by an early diagnosis.