One patient with acute and transient functional psychosis was assessed repeatedly using a brief neuropsychological assessment during his recovery from the psychotic episode. The psychotic features of the patient were characterized by perplexed behavior, attentional disturbance and emotional turmoil. Characteristic findings, including impairment of attention tests, dysgraphia and constructional disturbances, were seen. Findings improved in accordance with recovery on a behavioral level. We discussed the similarity of neuropsychological and behavioral abnormalities of this patient and those of patients in an acute confusional state.