Vein thrombosis and pulmonary embolism are severe complications that take second place among causes of death in hospitalized oncologic patients and often revealed after autopsy. Vein thrombosis and pulmonary embolism rates in oncologic patients are 4 – 15%. In addition new antiangiogenic medications can provoke coagulation system changes and following thrombosis. Thrombogenic risk factors depend on localization of tumor, blood red cells transfusions, narcosis duration, time of activation after surgery. Meanwhile it was estimated that low molecular weight heparin can inhibit angiogenesis. In 11 researches metaanalysis Kuderer et al. (2005) reported statistically significant advantages of anticoagulant therapy in oncologic patients. Thrombogenic complications prophylaxis can be mechanical and medicamental. Low molecular weight heparin supposed to be more effective than ungraded heparin. 3 large-scaled double blinded placebo controlled researches demonstrated efficiency of anticoagulants prophylactic prescription. Anticoagulants are proposed for prophylactic prescription in patients with urological malignant diseases due to vein thrombosis and pulmonary embolism rates decrease and its cost-effectiveness. 4 weeks prophylactic course of anticoagulants in combination with mechanical methods is advisable in high-risk patients. In addition anticoagulant treatment is recommended for 1 month after surgery.