One of the urgent problems in urgent abdominal surgery remains acute disseminated peritonitis (AP), the mortality rate of which remains high due to the development of multiple organ failure syndrome, despite the use of modern methods of diagnosis and treatment.The purpose of the study. To substantiate the possibility of using laparoscopic methods of treatment depending on the severity and stage of morphological changes of the target organs and the duration of peritonitis simulated in the experiment.Material and methods. The experiment used 150 sexually mature non-linear female rats, weighing 180.0-220.0 grams, which were kept on the standard ration of the vivarium of the Central Research Laboratory with maintenance of food and drinking regimes recommended by the norms of keeping laboratory animals. The animals were divided into 5 groups – a control group (30 rats) and 4 experimental groups (120 rats), which underwent HP simulation by intraperitoneal injection of 1 ml of 30 % autocal. The animals of the research group were removed from the experiment under sodium thiopental anesthesia by bloodletting on the 1st, 3rd, 5th, and 7th days. Results of the study. Morphohistochemical study of the target organs on the 1st day of the experiment: singleorgan changes were observed (examination of the peritoneum revealed its pronounced swelling). A slight vascular reaction of the basal membrane of the mucous membrane was established in the small intestine. On the 3rd day, the changes remained monooraneous with increases in infl ammatory phenomena. On the 5th day, the spread of the systemic infl ammatory response to the lungs and kidneys was confi rmed. Areas with foci of dystrophic- necrotic changes in the epithelium of the tubules were visualized in individual excretory tubules in the kidneys.In the lungs: the number of erythrocytes and fi brin increased in the cellular component. On the 7th day of the experiment, the heart and liver were involved in the process. In the heart, dystonia and paresis of microcirculatory vessels, erythrocyte stasis, and the formation of cell aggregates in the lumen of vessels were observed. In the liver, it is observed: congestion of the central veins, manifestations of venous stasis.Conclusion. Based on the stages of morphological changes of the studied organs at diff erent times, the simulation of acute peritonitis allowed us to theoretically justify a diff erentiated approach to the selection of the type of surgical interventions.