Deep vein thrombosis and its potentially fatal complication, PE, accounts for more than 250,000 hospitalizations annually in the United States. Pulmonary embolism is the most serious complication and has a 3-month mortality of 17%. Two million people each year are affected by VTE, and the prevalence is rising because of the aging population. Deep vein thrombosis and its potential complication, PE, is preventable. However, there still is widespread failure to screen, diagnose, and initiate prophylactic therapy in patients at risk. This failure can be corrected by development of a heightened awareness of risk factors among emergency department physicians and nurses and by similar personnel caring for bedridden hospitalized patients. A recent landmark study Prophylaxis in Medical Patients With Enoxaparin Study (MEDENOX) revealed the risk factors of VTE in order of frequency: (1) previous VTE, (2) acute infectious disease, (3) cancer, (4) age greater than 75 years, and (5) chronic respiratory disease. This study confirmed the effectiveness of a LMWH, enoxaparin, in the prevention of VTE.