Venous thromboembolism (VTE) is associated with short- and long-term morbidity and mortality. Strategies to identify and stratify patients at risk for VTE and guidelines for its prevention are discussed. VTE, which includes deep venous thrombosis (DVT) and pulmonary embolism (PE), is a common and potentially fatal health problem. An estimated 2 million patients in the United States will develop a DVT annually. Although VTE is asymptomatic in many patients, the risk of mortality remains high--approximately 100,000 deaths annually in the United States--despite the availability of effective treatments. Many patients who initially survive a PE die within 90 days of discharge. VTE is also associated with long-term consequences, such as recurrent VTE and the disabling and costly postthrombotic syndrome (PTS). VTE produces a significant economic burden due not only to the direct medical costs associated with acute inpatient care but also to the long-term, follow-up costs. The routine use of prophylaxis to prevent VTE is justified due to high prevalence, asymptomatic nature, long-term morbidity, high mortality rate, and cost of the disorder. Health-system pharmacists can help to diminish the risk of VTE by identifying and stratifying at-risk patients and ensuring that appropriate prophylaxis is provided. Implementing a methodical and aggressive approach will reduce the incidence as well as the morbidity, mortality, and cost associated with VTE.