OBJECTIVE: The purpose of this review, which also includes the report of a new case, is to discuss the pervasive denial of responsibility among individuals who have engaged in Munchausen syndrome by proxy (MSBP) behavior. In MSBP, a caretaker (almost always the mother) fabricates or induces illness in her child; she then presents the child for medical treatment, disclaiming knowledge of the etiology of the illness. METHOD: Literature searches of several computer databases were performed, and ninety-two citations dealing with MSBP, culled from medical, legal, and lay publications, were examined for descriptions of caretakers' responses to being confronted with the allegation of MSBP. Thirty-four citations contained relevant material, which was combined with observations from cases in which the author has served as a consultant. RESULTS: Caretakers engaging in MSBP consistently deny any role in the dissimulation, even when confronted with compelling evidence. This denial complicates management, though intervention must focus on ensuring the safety of the child regardless of the caregiver's response. CONCLUSIONS: Techniques sometimes advocated in factitious disorders in general may be useful in stopping the abusive behavior; however, no consistently effective strategy for overcoming denial in MSBP has yet been described.