Based on comparing results of tests followed in the present work between the endotoxin model of the disseminated intravascular coagulation (DIC) and irradiated groups of rats we consider that after the whole-body irradiation by a high dose of 250 Gy, the DIC occurs, in spite of the fact that the first stage--hypercoagulation condition, can be hardly observed. In the experimental endotoxin model, an increase of activated partial thromboplastin test (APTT) values and prolongation of the thrombin time was observed up to 24 hours in both endotoxin doses. After both endotoxin doses, the fibrinogen level was transiently decreased with its subsequent increase. The fibrin monomers correspond to decreasing the fibrinogen level. After the first dose, they were positive between the 3rd and 12th hours and after the second dose, the positivity was observed 6 hours after the application. The antithrombin III level was decreased after 12 hours in both endotoxin doses. The thrombocyte count was considerably reduced already from the 6th hour after administering endotoxin to the end of the experiment. Considerable changes of the thrombocyte aggregation were observed only 3 hours after administering the second dose. When comparing the resulting values of these tests with values observed in irradiated animals, then we can see a certain agreement in the nature of the changes after the exposure to 250 Gy. The fibrinogen level was transiently decreased 3 hours after irradiation, when considerable changes in the thrombocyte aggregation also occurred.