For many years, the structures of the medial temporal lobe have been implicated in the pathogenesis of schizophrenia. Recent hypotheses, based on data from MRI and functional imaging, propose that disruption of frontotemporal neural networks may be an anatomical substrate of schizophrenia. Many studies have focused on possible abnormalities of the hippocampus within this network. However, the role of the amygdala has been little studied because of the relative complexity of its structure and the paucity of patients with confined amygdaloid lesions. The authors present a case of chronic psychosis in which postmortem findings reveal lesions in and adjacent to the left amygdala. They use this case to review what is known of the functional anatomy of the amygdala and its possible role in some psychoses.