Background. The priority areas of the problem of acute widespread peritonitis (AWP) include the standardization of terminology and classification, assessment of the severity of the process, control of the infection source and correction of pathological intra-abdominal syndromes. Objective. To outline the conceptual aspects of AWP surgical treatment based on consensus guidelines and own research. Materials and methods. The study involved 371 patients with AWP. Patients underwent the necessary clinical, laboratory, biochemical, bacteriological, radiological, instrumental and pathomorphological studies. Results and discussion. To assess the severity of the disease one should assess the general clinical condition of the patient, the source and the site of infection, the presence or absence of organ or multiorgan dysfunction, the characteristics of the pathogen. The assessment of the clinical condition takes into account the patient’s age, physiological status and comorbid diseases, the general scales ASA, SOFA, APACHE, Marshall and peritonitis-specific scales (Mannheim Peritonitis Index, Peritonitis Index Altona). When determining the infection source, it is advisable to determine whether the process is provoked by damage to the upper or lower segment of the gastrointestinal tract. The most common causes of AWP in the own study were acute appendicitis (23 %), perforated gastric ulcer (21 %), acute pancreatitis and pancreatic necrosis (18 %). Acute cholecystitis, intestinal perforation, and anastomosis failure were somewhat less common. Suboperative measures during AWP surgery include detection and assessment of the source of the pathological process, elimination of the detected changes, lavage and adequate drainage of the abdominal cavity, correction of intra-abdominal pathological syndromes, clarification of the feasibility of programmed relaparotomy. Dekasan (“Yuria-Pharm”) is used for lavage. It is a local antiseptic, effective against gram-positive and gram-negative bacteria, viruses, and fungi. Dekasan is a surfactant that removes fibrin, pus, colonies of microorganisms and blood clots. According to V.V. Boiko et al. (2012), abdominal lavage with the help of Dekasan reduces postoperative mortality by almost 9 %, and the frequency of secondary purulent complications – by 16.5 %. Pathological intra-abdominal syndromes that need correction include abdominal compartment syndrome (ACS), intestinal insufficiency, and the excessive colonization of the proximal small intestine by pathological microflora. Prolonged tubal decompression of the small intestine, hyperbaric oxygenation, VAC-therapy, and application of negative pressure are used to decrease intra-abdominal hypertension in ACS. Tube techniques used in AWP include enteral lavage, enterosorption, selective pharmacological decontamination, and intraluminal transtubal electrophoresis. It is advisable to introduce enteral nutrition early. For additional detoxification and correction of water-electrolyte balance, low-volume infusion therapy with hyperosmolar solutions (Reosorbilact, “Yuria-Pharm”) is used. Reosorbilact contains sorbitol, sodium lactate and the necessary ions. Conclusions. 1. Modern approaches to solving the problem of AWP should be based on modern terminological and classification principles and provide an understanding of the content of surgery and the validity of antibiotic therapy. 2. Control of the source of peritonitis includes its complete elimination, lavage and drainage of the abdominal cavity, ensuring the decompression of the digestive tract with the implementation of a tubal program of measures. 3. Antibiotic therapy and infusion therapy are the important components of treatment. 4. The implementation of these statements will increase the effectiveness of AWP treatment.