The purpose of the study is to assess in vitro the effect of colloidal blood substitutes on fat globules in the blood of patients with severe polytrauma.Materials and methods. Perftoran, 5% albumin solution, dextran-40, dextran-60, modified gelatin, hydroxyethyl starches 200/0.5 and 130/0.42 were added to the blood of 19 patients with severe polytrauma at ratios 1:20, 1:10, 1:5 and 1:3, respectively, which corresponded to the addition of 0.015 ml, 0.03 ml, 0.06 ml, 0.1 ml of the blood substitute under test to 0.3 ml of blood in a tube. Microscopy of the samples with assessment of the number and area of fat globules was carried out using a transmitted-light medical microvisor mVizo-101 (LOMO, Russia) 30 minutes after the blood and blood substitute exposure and subsequent staining with Sudan IV. The findings were processed using JMicroVision 1.2.7 software.Results. Dextran-60, hydroxyethyl starch 200/0.5 and 130/0.42 in vitro lead to a decrease in fat globules in the blood of patients with severe polytrauma in proportion to the dilution degree. Modified gelatin, dextran-40, 5% albumin solution and Perftoran have a significant additional emulsifying effect on the fat globules. The maximum emulsifying effect was obtained after addition of Perftoran to the blood.Conclusion. The experimental data on the effect of 5% albumin solution, modified gelatin, dextran-40, and Perftoran on fat globules justify the prospect for their further clinical application for prevention and treatment of fat embolism in an extended clinical trials.