Munchausen by Proxy (MBP) (Factitious disorder by Proxy) is a special kind of child abuse. A family member or especially a caregiver creates or fabricates illness in a child. One of the suggested reason for this syndrome is the “caregiver unconsciously undertakes the role of patient”, another reason is the “fulfillment felt by the caregiver of giving care to someone who is in hospital”. The purpose of this study is to discuss MBP with a content of “exposure to sexual abuse”. A 13-year-old male patient was brought to our child psychiatry clinic by his mother with a complaint of being exposed to sexual abuse. The first admission was in 2007. The mother stated that the custody of the child was given to the father after the parents got divorced and that she was taking her son for a month during summer time. The mother stated that in the summer of 2007, when she took her son to live with her, her son mounted on her in a way that his penis could get in her mouth, he squeezed her head with his legs and tried to put his penis in her mouth, he told her to “take it and suck it”, he made moves similar to adults’ sexual intercourse by mounting on her in a way that his penis was on her genitals and wanted her to play with his penis after he peed. The mother came to our Child Psychiatry Clinic again in 2013. She said that her son was taken away from school and beaten up, he was abused by being kissed from his lips, his underwear was torn and she thought that he was being abused. In different interviews, it was observed that the mother’s statements were inconsistent and in the following hours of the interview, she was observed to show emotions, which were inconsistent with her mood while telling the events. The patient was not found to have psychiatric symptoms or findings that could result from sexual abuse and MBP diagnosis was considered. Later, the mother was referred to adult psychiatry and social observation was planned. If the parent’s psychopathology is a mental illness like MBP that exposes the child to a neglect or abuse, it should be considered that the child is in a serious mental risk. As the age of the abused child increases, it has been reported that the child actively begins to participate in this deception of the parent. This situation may cause ignoring the diagnosis. Such a situation was observed in our case. However, factors such as the mother’s showing no emotional weight and her indifferent appearance caused us to consider MBP diagnosis. With this presentation, we wanted to emphasize the need to consider the possibility of MBP in patients who are brought with allegations of being exposed to sexual abuse.