A study of cerebral ventricular size measured as ventricle to brain ratio (VBR) using computerised tomographic brain scan in chronic schizophrenics provided no support for suggestions that there are significant differences between patients who fall into different clinical subtypes. We found no significant difference in VBR between patients with and without a family history of schizophrenia or between those with or without paranoid symptoms. Applying Crow's classification, contrary to expectations, Type 1 patients had significantly larger ventricles than those with 'mixed' symptomatology (both Type 1 and Type 2 features). We also applied a variety of operational criteria which attempt to define schizophrenia as a whole: of these only Schneider's first-rank symptoms (FRS) yielded conclusive results--FRS-positive patients had significantly larger mean VBR than those without such symptoms. Previously, it has been suggested that ventricular enlargement is more closely associated with 'negative' than with 'positive' symptoms.