Validity and interpretation of neuroradiological findings in schizophrenics are still discussed controversially. This applies also to some adjacent functional diagnostic techniques, which could possibly give support to neuroradiology, as post-mortem histopathological examination, electrophysiological recording, and positron-emission tomography. One of the causes for the inconclusive findings could be the patient- and control-group sampling, which is despite standardized diagnoses still heterogeneous in factors determining ventricular size. This heterogeneity applies also to the adjacent functional-diagnostic studies. A prevalence of enlarged ventricules of about 10% in schizophrenics is largely assumed, the measurements within the normal range tending to be somewhat higher than in the control-groups as well. Inconsistently a relation is reported between enlarged CSF-spaces on one side and unfavourable premorbid adjustment, chronic course of the illness, and predominance of negative symptoms on the other side. The CT findings in twin- and family studies stress also the etiological impact of brain morphology on schizophrenia. Size and width of ventricles in schizophrenics seem to be determined genetically as well as environmental. Most recently findings of unusual laterality or blurring of physiological lateral organization in the central nervous system gain growing interest. In this area brain-morphological findings are supported and supplemented by electrophysiological and PET-findings. For interpretation most authors at present refer to the hypothesis of 2 subgroups of schizophrenia, with and without dementing factors. The author suggests the view, that there is a common feature in all the heterogeneous and contradictory biological findings: They generally indicate a loss of cerebral organization.(ABSTRACT TRUNCATED AT 250 WORDS)