Structural brain abnormalities in schizophrenia have been reported by several computertomographic (CT) studies. However the prevalence and the, localization of the abnormalities vary widely among studies. These differences might stem from samples heterogeneity, from the choice of the CT parameter to be investigated and from the use of different criteria for defining abnormalities. In spite of some contradictory findings, it seems stablished that at least one subgroup of schizophrenic patients shows mild or moderate brain atrophy; this subgroup might be characterized by a chronic course of the disease, poor response to neuroleptic therapy, and the presence of other neurodiagnostic signs of a diffuse brain dysfunction such as neuropsychological impairment, EEG abnormalities and neurological «soft signs». Atrophic findings have been observed in young schizophrenic patients at the first onset of the disease, indicating that the development of the structural abnormalities are not a consequence of a chronic disease and treatment. Schizophrenics with atrophy are unlikely to have a genetic loading (family history) with schizophrenia and they present more frequently pregnancy and birth complications as well as brain trauma in the first years of development. Because schizophrenics with brain atrophy might represent a more homogeneous subgroup with regard to clinical and aetiopathological variables, it is still an important task to identify more precisely these patients on the basis of CT data and then to study the features that could characterize this subgroup.