Although worldwide prevalence has decreased with the onset of antibiotic therapy, syphilis plays an important role in modern medical and psychiatric practice. Neurosyphilis, a Central Nervous System infection caused by the spirochete Treponema pallidum
, is a serious pathology that leads to deterioration of the disease with a significant impact on his life and also on the caregivers’. The authors propose a brief review of the topic based on the clinical cases of two patients admitted to sudden manifestations of cognitive and behavioral changes diagnosed with neurosyphilis, reflecting on the importance of the exclusion of organic causes and the treatment of psychiatric symptomatology. These events are usually diagnosed as rapidly progressive dementia, which may be due to different causes, so that the psychiatrist must assume a high degree of suspicion. Although there is a standard treatment with penicillin for neurosyphilis, in the current literature there is no evidence regarding the treatment of its psychiatric manifestations, altough there is an apparent benefit in the judicious use of antipsychotics.