This chapter talks about a 39-year-old man, a human resource executive, who was seen at the outpatient clinic of the Behavioral and Cognitive Neurology Unit of the Hospital das Clı´nicas, a public university hospital in Sao Paulo, Brazil. Physical examination showed a well-nourished man, with a blood pressure of 130/80 mmHg, and neurologic examination revealed only dysarthria, with normal and reactive pupils and normal reflexes. His insight about his problems seemed to be normal. The initial diagnostic impression was a Frontotemporal Dementia (FTD), but the final diagnosis was of paretic dementia, a neuropsychiatric condition caused by neurosyphilis. He was treated with intravenous aqueous crystalline penicillin G, 4 million units every 4 hours for 21 days, and with fluoxetine. FTD or behavioral subtype of fronto-temporal lobar degeneration was the initial diagnosis in this case because the clinical picture was dominated and confirmed the presence of frontal or fronto-temporal involvement.