Hemostatic changes were studied in 67 phthisiosurgical patients 2-3 days prior to surgery and in the early postoperative period. It has been found that blood coagulative disorders following lung surgeries with a small volume of blood loss require no special corrective measures. After massive blood loss there are pathological changes requiring correction of coagulation factor deficit. The policy of transfusion support which is based on substitution of blood loss with donor blood by 35-50% and blood-substituent solutions which exceed its volume by 1.7-2.8 times ensures the optimal maintenance of hemostasis with small and moderate intraoperative blood loss. Patients with massive blood loss develop hemostatic changes requiring replacement therapy to compensate losses of the coagulation factor.