The article presents a case of a fatal outcome of a 15-year-old teenager with cerebral vascular thrombosis, which developed in the post COVID-19 period. The young man came in with complaints of headache, vomiting, photophobia, hyperacusis. It was known that at an early age he had been operated on for the Arnold – Chiari anomaly, had a subdural-peritoneal shunt. Two weeks before hospitalization, he suffered a new coronavirus infection of mild severity, which was confirmed by a positive analysis of a smear from the oropharynx by polymerase chain reaction. Cephalgia was acute, stopped for a short time after the use of analgesics. During the examination, the patient laid with his eyes closed, asked for silence and blackout in the ward. Any movement of the head was accompanied by dizziness, headache, vomiting. During an objective examination, no pathological changes were found on the part of the internal organs. The neurological status was determined by photophobia, double vision, asymmetric face, asymmetry of the eye slits S > D, drooping of the left corner of the mouth, nystagmus, hyperacusis. There was no rigidity of the occipital muscles. Meningeal signs were negative. There were no pelvic disorders. According to the laboratory examination, lymphocytopenia, thrombocytosis, acceleration of ESR, moderate increase in ferritin, D-dimers were detected. Conducted neuroimaging methods (MSCT of the brain with intravenous contrast, brain MRI, ultrasound diagnostics of cerebral vessels) did not find any blood clots in intracranial and extracranial vessels. Low-positive values of IgM antibodies to cardiolipin were revealed. According to the results of polymerase chain reaction, polymorphism G20210A was detected in the prothrombin gene. The patient received high-dose glucocorticoids and heparin for treatment. Despite the therapy, a month and a half after hospitalization, the teenager died from thrombosis of the central venous sinuses (cavernous sinus on the left, transverse sinuses, jugular veins), which were confirmed on autopsy. This clinical case of venous sinus thrombosis in a teenager in the post COVID-19 period presented diagnostic difficulties, since accurate imaging methods did not detect the presence of a blood clot in the cerebral vessels.