Introduction: Inflammatory and septic complications prophylaxis problem comes to improve the treatment’s outcomes of the worst polytraumatised patients, with open fractures of long tubular bones. The aim of the survey is to study the peculiarities of the changes in blood, of the procalcitonin index, at the severely polytraumatised injured, with high prevalence of the injuries of the locomotor apparatus. Materials & Methods: Were selected 20 patients with a high severity (ISS score - 18-40) of the polytraumatism. The study of the system of the blood hemostasis was performed after 24 hours (period of relative stabilization of vital functions), at the 3rd and 6th day after the injury, which coincided with the beginning and the end of the maximum possible development of the complications. Results: At the group of patients with a high severity of the polytraumatism without direct danger to life (ISS score - 16-24 points), over the course of the period of the research, wasn’t established a procalcitonin increase in the blood. From 2nd to 8th day of the traumatic disease, the values were less than 0.5 ng / ml. In dynamic, at no patient from this group, has not developed septic complications. A number of features have been detected in the group of patients with high-severity life-threatening multiple trauma (ISS score - 25-40 points). Compared with the previous group of patients, at five injured (50% of the group in question) was observed an increase of procalcitonin. Two women, aged 60 and 65, during the relative stabilization period of the vital functions, had the indicator above 0.5 ng / ml, with normalization in the period of the maximum potential development of complications [8]. Inflammatory complications at these patients in dynamic did not occur. At another two patients of working age, over 24 hours after the multiple trauma, received as a result of high energy impact factors (rail and road accident), the procalcitonin level in blood was > 2 ng / ml, at the beginning of the relative stabilization period of the vital functions. At another patient, to whom were not performed the prophylactic measures with two antibiotics with wide specter of action, the period of maximum development of the potential complications was aggravated by a massive phlegmon of the superior traumatized limb. Conclusion: The results revealed some aspects of specific changes in blood levels of the procalcitonin at the patients with multiple trauma with open fractures of long tubular bones. The clear increase (> 2 ng / ml.) of the procalcitonin index was observed only in case of massive devitalization of muscle tissue and development of active inflammatory process in the group with high severity life-threatening politraumatisms.