Munchausen syndrome by proxy (MSBP) is a rare form of mental disorder and is known as a particular type of child abuse. MSBP has been described since 1977 as a severe form of abuse with illness falsification or the intentional harming by guardians, mostly mothers. The perpetrator of MSBP may inflict damage to the child directly or indirectly through medical procedures. The perpetrator’s alleged motive is to satisfy her psychological needs, and she has a history of mental illness, mostly, factitious disorder, personality disorder, and somatic disorder. The pathology is not well known; as such, it is difficult for medical personnel to detect it early. In addition, it is hard to be handled effectively by the police and child welfare agencies because of the scarcity of evidence. Therefore, the authors attempt to examine the essential information from early detection and child abuse prevention by analyzing its clinical characteristics and the perpetrator’s characteristics, including alerting signs of MSBP. For this purpose, we focus on the role of nursing staff to detect this unusual cause of child abuse.