Hereditary haemorrhagic telangiectasia, or Rendu-Osler disease, is a congenital vascular disease that is associated with the presence of arteriovenous fistulas that cause paradoxical embolisms.An 83-year-old female with clinical signs and symptoms of convulsive attacks and multiple cerebral infarctions in the acute phase. She also presented a history of multiple haemorrhages and iron deficiency anaemia with no clear aetiological causation. A thorough examination of her medical history revealed a family history of haemorrhages and a sister who had been diagnosed with Rendu-Osler disease, which suggested the possible existence of a pulmonary arteriovenous fistula as the aetiological causation of her cerebrovascular disease. Neurovascular Doppler ultrasonography with bubble contrast test was positive, and the presence of the fistula was confirmed by a computerised axial tomographic angiography scan of the lungs.Rendu-Osler disease is a rare cause of stroke due to the fact that it is usually associated with arteriovenous fistulas that can cause paradoxical embolisms. Neurovascular Doppler ultrasound scanning is useful for detecting these pulmonary fistulas by means of the bubble contrast test, which is a non-invasive test that can be carried out easily by neurologists themselves.