This study's purpose was to describe compliance with established venous thromboembolism (VTE) prophylaxis guidelines in medical and surgical inpatients at US academic medical centers (AMCs). Data were collected for a 2007 University HealthSystem Consortium Deep Vein Thrombosis/Pulmonary Embolism (DVT/PE) Benchmarking Project that explored VTE in AMCs. Prophylaxis was considered appropriate based on 2004 American College of Chest Physicians guidelines. A total of 33 AMCs from 30 states participated. In all, 48% of patients received guideline-directed prophylaxis-59% were medical and 41% were surgical patients. VTE history was more common among medical patients with guideline-directed prophylaxis. Surgical patients admitted from the emergency department and with higher illness severity were more likely to receive appropriate prophylaxis. Despite guidelines, VTE prophylaxis remains underutilized in these US AMCs, particularly among surgical patients. Because AMCs provide the majority of physician training and should reflect and set care standards, this appears to be an opportunity for practice and quality improvement and for education.