A rare case of a tabes dorsalis in a 66-year-old man with a newly diagnosed HIV infection (stage 4B) is described. Late neurosyphilis (NS) and HIV infection were both diagnosed in the patient during an examination in connection with complaints of hearing loss, weakness of the mimetic muscles of the right half of the face, gait abnormality. Spinal troughs manifested as neuritis of vestibulocochlearis nervus and facialis nervus, tendon hyporeflexia, positive symptoms of Argyll Robertson syndrome, static and motor ataxia. Neurological symptoms corresponded to the onset of the atactic stage of the tabes dorsalis. The diagnosis was confirmed by the results of the study of cerebrospinal fluid. The patient was prescribed treatment with massive doses of intravenously injected penicillin, however, toxicoderma, which occurred on the 12th day of treatment, required replacement of the drug with reserve antibiotics. Against the background of specific treatment, a decrease in instability during walking was noted, but there was no positive dynamics on the part of inner ear and symptoms of paresis. HIV infection without antiretroviral therapy progressed, and after 3.5 months the patient died as a result of bilateral subtotal pneumocystis pneumonia. This case is of interest in respect of the rarity of tabes dorsalis and because of the unusually rapid augmentation of neurologic symptoms in association with progressive HIV infection. In the coming years, the number of cases of co-infection of Treponema pallidum and HIV is expected to increase and, consequently, the late forms of neurosyphilis are more likely to develop in HIV-infected patients.