In 1981, the Report of the Medical Consultants on the Diagnosis of Death established guidelines for the diagnosis of brain death and, in 1995, the American Academy of Neurology published practice parameters to standardize determination of brain death. In 1987, the American Academy of Pediatrics established guidelines for determining brain death in children. Despite the establishment of these guidelines, the declaration of "death" based on the cessation of brain function remains complex and controversial. In this review are discussed the current guiding principles and the controversies in the diagnosis of brain death in children.