The authors present a case of 24-year-old patient admitted to Neurological Department with ascending transverse myelitis symptoms with subacute course. At the admission neurological examination revealed: spastic paraparesis (3rd stage in the Lovette scale), sensory disturbances on the level Th9, and urinary incontinence. Asymmetry in thighs’ circumference was disclose (the difference was 4 cm, P>L). There were no pathological changes in CT scanning of spinal cord on the level Th7-Th11. In cerebrospinal fluid analysis increased cytosis and protein level were confirmed. During clinical observation the sensory level was ascending up to Th5. The worsening of lower extremities palsy and proctoparalysis were also observed. Spinal cord MRI examinations disclosed a huge spinal vascular malformation extended from C2 to level of cauda equina. Spinal magnetic resonance angiography (MRA) examination revealed a feeding artery from aorta at Th7-Th8 level with the possibility of additional vascularisation from intercostal arteries on the level Th12. This case indicates the rare aetiology of spastic tetraparesis, and necessity of AVMs consideration in the differential diagnosis of myelopathy apart tumours, infections, multiple sclerosis and other vascular diseases.