Cervical artery dissection (CeAD) due to arterial wall weakness (dysplasia) is one of the most common causes of ischemic stroke (IS) at a young age. A rare and little known cause of CeAD is Turner's syndrome (TS)-is an inherited disease caused by completely or partially missing X chromosome. In this paper, we describe 2 female patients, aged 27 and 33 years, with genetically confirmed TS (karyotype 45X0) and internal carotid artery dissection(ICAD).TS frequency among our 304 patients with CeAD was 0.07%. Both patients had short stature, received hormone replacement therapy from the age of 14 and had arterial hypertension. In addition, the first patient suffered from hypothyroidism, osteoporosis and survived a nephrectomy for hydronephrosis. ICAD in first patient manifested by IS. MRI of the neck arteries, MRA and CTA revealed intramural hematoma, hemodynamically significant stenosis, which regressed in 4 months. In the second patient, dissection was manifested by local symptoms (Horner's syndrome, cervicocephalic pain on the dissection side). MRA and CTA revealed a precranial dissected aneurysm of the left ICA (on the side of local symptoms), fusiform expansion of the right ICA, and pathological tortuosity of both ICA. The paper discusses the cause of vasculopathy in TS. It is assumed that connective tissue damage is associated with a deficiency of biglycan - extracellular matrix protein, which interacts with collagen and elastin to strengthen the arterial wall. Biglycan gene is linked to X-chromosome which is completely or partlially missing in TS resulting in a biglycan deficiency. The role of sex hormone deficiency as a cause of arterial wall weakness is unlikely.