The number of thrombotic events in children, although significantly less than that in adults, is increasing as a result of therapeutic advances in primary illnesses that were previously fatal. When a patient, adult or pediatric, develops a deep vein thrombosis and anticoagulation therapy is initiated, many health professionals ask, "When should this patient have physical therapy and/or ambulate?" Fear of causing a pulmonary embolism with increased activity drives this question. Often, an order for bed rest is prescribed based more on tradition than on evidence-based medicine. A review of the literature has provided an evidence-based answer to the question, and although the studies are all of adult populations, the results have been extrapolated for use with comparable pediatric populations. The majority of studies agree that early ambulation does not increase an anticoagulated patient's risk for pulmonary embolism. Moreover, most studies report that early ambulation carries benefits such as decreased pain and swelling and fewer postthrombotic syndrome symptoms.