In the pathogenesis of sepsis hemostatic disorders associated with changes in the functional activity of circulating platelets are important, which can be caused by both direct and indirect effects of bacterial lipopolysaccharides. Due to the disparity of methodological approaches, the effect of endotoxins on the kinetics of platelet aggregation has not been sufficiently studied at present, an understanding of which is necessary for the reasoned appointment and screening of promising antithrombotic and anti-inflammatory drugs. The purpose of this work was to study the effects of Salmonella enterica lipopolysaccharide on the aggregation activity of rat platelets by optical aggregatometry in ex vivo and in vitro conditions.