The mechanisms of antihypotensive action of antishock overalls (ASO) were studied on the basis of comparison of 30 patients with traumatic shock at the prehospital stage of medical care; in 15 of these ASO was used, in the other 15 traditional antishock intensive care. Use of a portable device for noninvasive measurement of cardiac stroke volume at the prehospital stage permitted us detect the principal mechanisms of liquidation of shock-induced arterial hypotension with the use of ASO: increase of cardiac output at the expense of autohemotransfusion from the lower part of the body to the upper vital organs with increase in the volume of venous blood restitution to the heart, the increase of total peripheral vascular resistance being negligible. Use of ASO in a complex of intensive care measures for the treatment of traumatic shock at the prehospital stage is physiological and conducive to optimization of medical care rendered to victims at the early stages of treatment.