Introduction. Tertiary syphilis is a rare systemic disease, which describes the final stage of syphilitic infection. It is associated with late form of neurosyphilis and often occurs in untreated patients. Case presentation. We present the case of 63-year-old immunocompetent man with a history of nodular and nodular-ulcerative lesions, some of them covered with crusts. He denied any signs of primary and secondary phases and any previous treatments. On the neurological examination, we revealed paresis of oculomotor nerve on the right side, facial asymmetry on the left side, the involvement of the vestibular part of the VIII nerve and cerebellar ataxia, extrapyramidal symptoms and dementia changes. We also noticed the presence of the Argyll-Robertson pupils sign and, later, urine and fecal incontinence. The patient was diagnosed with tertiary syphilis accompanied by late form of neurosyphilis based on the clinical symptoms, morphology of the lesions, positive serological serum and cerebrospinal fluid tests. A cerebral CT showed cortical atrophy and dermatopathological examination revealed infiltration of lymphocytes and plasma cells without granulomas. Conclusions. Tertiary syphilis is a large diagnostic challenge. The difference should be made between late recurrence in secondary syphilis with ulcerative lesions following deep pustules on one hand, and nodular-ulcerative, eventually gummatous, lesions of tertiary syphilis on the other hand. The other point favoring tertiary syphilis is the persistence of the nodular lesions under antibiotic treatment. Although the syphilis can affect nervous system at any stage of the infection, it is more common to manifest symptoms during the late form of syphilis.