Chromosomal fragility and other chromosomal abnormalities were frequently observed in subjects with neuropsychiatric disorders, such as fragile X syndrome, autism or schizophrenia, but only for the first one the fragility is accepted to be associated to a specific pathology, so that it is used as a diagnostic marker. In this study the authors analyzed 50 schizophrenic males, searching for the rare fragile sites or other aberrations with the method suitable for fra(X) detection. Chromosomes from schizophrenic patients resulted more fragile than those from normal controls, especially chromosome 9. The authors discuss the implications of a possible association of these data with the aetiopathogenesis of schizophrenic syndrome.