Deep vein thrombosis (DVT) and pulmonary embolism (PE) are leading causes of morbidity and mortality in the United States. Estimates range between 300,000 and 600,000 hospitalizations a year, with approximately 50,000 deaths related to PE. The incidence of the complication of DVT following total joint replacement is reported to occur in 50% to 75% of all unprotected patients. The increasing number of adults who undergo a total joint replacement dictates that orthopaedic nurses become a vital part of the development team that (1) identifies contributing factors to each patient's risk profile, (2) decreases this risk, and (3) refines the patient's transition through the acute hospitalization into the home or rehabilitation environment. The results of recent studies with a new class of heparins, the low molecular weight heparins, suggest their superiority and demonstrate improvement in decreasing the risk of developing DVT and subsequent PE in the total hip and knee patient population.