The risk factors of venous thromboembolism (VTE) in 1146 patients who were underwent operated for the diseases of digestive organs, for obliterating atherosclerosis of abdominal aorta and peripheral arteries, diseases of bones and joints were studied. The methods of VTE prevention in these patients were studied. To evaluate the risk of VTE we designed the special chart. Three levels of risk of VTE: low, moderate and high were distinguished. The specific prophylaxis of the VTE using low molecular weight heparin fraxiparine was given to the patients moderate (90.7%) and high (93.3%) risk degree.