Twenty-three drug-free patients with an acute schizophrenic psychosis were studied by clinical rating scales, neuropsychological tests, computed tomography (CT) of the brain and analysis of monoamine metabolites in the cerebrospinal fluid (CSF). The psychological tests used were the Swedish version of the Wechsler-Bellevue Intelligence scale (WBI) and the Block Design test. The patients' performance in the Block Design test was negatively correlated to the width of the third and lateral ventricles. Test profiles indicative of schizophrenic cognitive impairment and left hemisphere dysfunction correlated significantly with a wide third ventricle, but not with the size of the lateral ventricles. Patients with a test profile indicative of left hemisphere dysfunction also had wider Sylvian fissures than the remaining patients. Neuropsychological test scores did not correlate with the CSF levels of the monoamine metabolites HVA, MHPG and 5-HIAA. Positive psychotic and autistic symptoms did not correlate with psychological test results, monoamine metabolites or with CT measures. The association between neuropsychological impairment and enlargement of the brain ventricles is in line with previous findings indicating that a subgroup of schizophrenic patients may be identified by neuropsychological and morphological methods.