Venous thromboembolism (VTE) is a serious medical problem and is one of the most important preventable causes of mortality and morbidity in hospitalized patients. This article reviews the prevention of VTE with thromboprophylaxis in acutely ill general medical patients. We review recent studies which show that general medical patients are at moderate risk of VTE and that low-molecular-weight heparin reduces this risk. Nurses have a key role to play in changing clinical practice by increasing awareness of the risk of VTE in medical patients, helping in the process of risk assessment and ensuring appropriate prophylaxis.