Introduction. Only a massive radiation accident, and not individual incidents heterogeneous in terms of exposure conditions, contributes to the revision and development of knowledge and therapeutic capabilities in acute radiation syndrome (ARS). Aim — to present recommendations based on literature data and own clinical experience for the diagnosis and treatment of a typical bone marrow form of ARS from relatively uniform irradiation. General information. An analysis of the literature on the problem of diagnosis and treatment of ARS was carried out, and the experience of providing medical care to victims of the April 26, 1986 radiation accident at the Chernobyl Nuclear Power Plant (104 patients with OLB) in the clinical department of the A.I. Burnazyan State Medical Center of the FMBA of Russia is summarized. When admitting individuals involved in a radiation accident into a medical institution, one of the most important measures of action is to conduct medical sorting, that is, the distribution of victims into groups according to the principle of need for homogeneous therapeutic, preventive and evacuation measures, depending on medical indications, specific conditions of the situation and the prognosis of the patient's survival based on dose assessment and prediction of the severity of the course of ARS by all available methods of physical and biological dosimetry (calculation method, simulation of the situation, clinical signs of the primary reaction to radiation, cytogenetic method, absolute number of peripheral blood lymphocytes during the first 8 days after irradiation, dynamics of the absolute number of peripheral blood neutrophils, etc.). The scope of therapeutic measures depends on the severity of the developing ARS, including the therapy of infectious complications and hemorrhagic syndrome. The appointment of myelostimulation in order to reduce the depth and duration of radiation-induced cytopenia is recommended when irradiated at a dose of more than 1.5 Gy. Transplantation of allogeneic hematopoietic stem cells in ARS is recommended in a narrow dose range from 10 to 13 Gy in the absence of concomitant severe injuries and burns. Recommendations for the treatment of oropharyngeal and intestinal syndromes are given.