The number and morphological types of megakaryocytes (MK) in the rat inferior cava vein blood were evaluated in untreated hemorrhagic shock lasting 60 min and in 6 to 48 hours after treatment with a standard polyelectrolyte solution (PES). The rats were bled through carotid artery. MK were isolated using the 5 microns filters. The results were compared with those found in the control animals not subjected to surgical manipulation and subjected to sham operation (cervical incision only, and cervical incision + carotid artery cannulation). The most considerable increase in the circulating MK occurred in 12 hours after the PES treatment. The slight increase in the number of MK was also observed in rats with carotid artery cannulation without hemorrhage. Increase in the MK number was accompanied by a shift in their morphological types.