The authors present a case of neurosyphilis associated with predominant psychiatric symptoms. The elderly man was admitted because of confused behavior, maniform state, lack of critical judgement and grandiose delusions. On admission, right central facial nerve paresis, hand tremor and parkinsonism were also found. Acute brain imaging and routine laboratory tests failed to identify a firm etiology of the confusional state. The psychiatric treatment resulted in complete recovery from delirium. Afterwards, maniform psychosis dominated the clinical picture for which antipsychotics were administered. Later, rapid cognitive deterioration and progression of motor symptoms were observed. MRI revealed cortical and hippocampal atrophy and white matter hyperintensities. Lumbar puncture found pleocytosis and elevated cerebrospinal fluid protein levels. Neurosyphilis had been confirmed by serologic tests. The cognitive symptoms improved and the psychiatric symptoms remitted under penicillin treatment. Four years after diagnosis, there is a gradual progression in the cognitive decline. Two additional hospitalizations were necessary due to the relapses of psychiatric symptoms. Orv Hetil. 2018; 159(6): 234-238.