Deep vein thrombosis and pulmonary artery thromboembolism are the most commonly occurring cardio-vascular complications of oncological diseases, which may develop at any stage of the oncological process. These life-threatening complications take the leading positions within the structure of mortality among cancer patients, giving place only to the oncology disease itself. It is important to note that the patients with cancer-associated thromboses are the most difficult group of patients, in which the development of thromboses and thromboembolisms may not only delay the vitally important treatment of the main disease, but also to completely cease the treatment due to the lack of possibility for its adequate performing. This is an important social and economic task, taking into consideration the costs for the healthcare system required to treat the disease itself and its concomitant complications. Thus, there is a criticality factor of not only the treatment itself, but also of the prevention of oncology-associated thromboses and thromboembolisms. Currently, due to the wide spreading of the said complications, the therapy and the prevention of them undergo significant changes. The traditionally used warfarin is being switched to low molecular weight heparin. At the present moment, oral anticoagulants are used more and more often. The analysis of special scientific literature has allowed for evaluating the novel principles of treatment in cases of oncology-associated thromboses and thromboembolisms depending on the location of the process, on its stage, on the severity of the patient status, as well as to define the risk factors of oncology-associated thromboses, the practicability and possible methods of its prevention in various groups of patients.