We observed acute onset of delayed psychosis in 8 patients 1 month to 11 years after right temporoparietooccipital (TPO) stroke or trauma. The psychotic disorder included hallucinations and, in some patients delusions and agitation. All patients had spatioconstructional difficulties. None had an earlier psychiatric disorder. Seven of eight patients had clinical seizures, often in close temporal relationship to the psychosis. The pathophysiology of the psychosis may be related to that of the epilepsy.