ICVT can be safely observed in asymptomatic patients without therapeutic anticoagulation. In our study, patients who have had orthopedic procedures, those with malignancy, and those that were immobile seemed to have a higher incidence of clot propagation. In this group, we recommend full anticoagulation until the patient is ambulatory or the follow-up duplex scan is negative. Our data also suggest that a follow-up duplex scan is not beneficial when performed within 72 hours or after 3 months.