SummaryWe report on the case of a patient who developed an acute meningitis and, after a period of about two weeks, without any neuropsychiatric problems, an acute paranoid-hallucinatory and catatonic syndrome. The symptomatology is discussed, in relation with the diagnostic difficulties of differentiating between a biphasic meningo-encephalitis with an organic psychosis or a first manifestation of an endogenous psychosis.
