Diagnosis of cerebral syphilitic gumma is frequently determined at the time of surgery, because imaging and laboratory findings demonstrate the elusive results. A 59-year-old woman presenting dysarthria showed a mass on her brain computed tomography. She was first suspected of brain tumor, but histological results from surgical resection revealed cerebral gumma due to neurosyphilis. After operation, she presented fever and rash with an infiltration on a chest X-ray. Histological assessment of skin was consistent with syphilis. Fluorescent treponemal antibody absorbed test IgG in cerebrospinal fluid was positive. She was successfully treated with ceftriaxone for 14 days.