Background: The pulmonary thromboembolism (PTE) has demonstrated a serious evolution and a high lethality level and is on the third place as a cause of a sudden death and remains one of the most actual issues in medicine. The actuality of the problem consists not only in the disease severity and lethality, but also in the difficulties in the diagnostics. Material and methods: By the necropsy data, the incidence of PTE is estimated as about 15% of cases. A retrospective study of 33 patients who died from PTE in the period of 2008-2013 is presented. In the studied group the following risk factors have been identified: intravenous catheters, surgery, immobilization in bed, smoking and atrial fibrillation. In the studied group PTE prophylaxis has been performed with heparin, nadroparin and enoxaparin. The authors have been dissatisfied with the research due to PTE fatality. Results: It has been revealaed that an important factor in decreasing the lethality is the administration of antiplatelet drug support to all the patients with PTE risk. Conclusions: 1. PTE is a frequent complication with a high lethality even in the case of its prevention. 2. The presence of risk factors, regardless of their number, strongly requires a preventive treatment. 3. The most effective anticoagulant drugs at the moment are those from the group of anticoagulants with a low molecular weight in preventive doses (Fondaparinux, Enoxaparin, Nadroparin). 4. It is necessary to reevaluate the anticoagulant medication support and prescribe it to the people above 40 years old. 5. The problem of PTE remains open for the further research with regard to the evidences of risk factors and the lethality decrease.