A comparative analysis of 2 groups of patients: 97 people with vertebro-basilar insufficiency (VBI), mean age 48,14±10,45 years, and 54 people with the vertebrogenic syndrome of spinal artery (VSSA), mean age 41,66±10,98 years, were studied. All patients underwent a neurological examination with the assessment of clinical symptoms (in scores) on the scale of vertebral-basilar deficiency (Hoffenberth, 1990), ultrasonic dopplerography and transcranial dopplerography of cerebral vessels with functional loading tests (hypo- and hyperventilation, ortho- and antiorthostatics, head rotations). Differential clinical and dopplerographic characteristics of these pathological states were singled out. Psychoemotional distress, static or dynamic overloading and cervical trauma significantly dominated in the anamnesis of patients with VSSA, while the patients with VBD more frequently had vascular risk factors. In patients with VSSA, the total score on the Hoffenberth scale was 5-7 and that of objective neurological symptoms was less than 2. In patients with VBD, these scores were >8 and >2, respectively (p=0,001).The dopplerographic examination revealed signs of the combined lesion on different levels of vertebral-basilar (hemodynamically significant) and carotid (more frequently, hemodynamically nonsignificant) basins in patients with VBD. Dopplerographic signs of the hemodynamically nonsignificant lesion of spinal artery on the extracranial level were found in patients with VSSA. The isolated vertebrogenic compression does not lead to the blood flow deficiency in the vertebral-basilar basin but in the course of time, with the addition of lesions of other cerebral arteries, VSSA may transform to VBD.