MBP involves the fabrication of a condition (usually medical, but sexual abuse, educational deficits, and psychiatric illnesses have also been reported) by a caretaker (most often the mother) to assume the role of a sick patient through a proxy (the child). Since Munchausen by Proxy is a confusing term, there is a growing consensus that Factitious Disorder by Proxy (FDP) is a better description of the condition in the mother. There has been only one carefully done study of FDP, which focused on only two conditions, i.e., poisoning and suffocation. This British study (McClure et al., 1996) can be translated to estimate 1,200 such new cases of these conditions in the United States each year. Because the diagnosis of FDP depends upon a diagnosis of Pediatric Condition Falsification (PCF) and the diagnosis of the latter depends upon statistical improbabilities of the course of an illness, false positive diagnoses are a possibility that must be carefully considered. FDP should not be diagnosed when a family with a chronically ill child is genuinely dissatisfied with the care, seeks second opinions, or has suggestions that involve alternative medicine. This chapter discusses approaches to diagnosis, the membership of an interdisciplinary treatment team, case disposition, and the role of the child's or family's physician. Three relevant case vignettes with follow-up questions are presented. 18 references