Sixty patients with documented moderate-to-severe pulmonary embolism have been managed primarily with anticoagulant or lytic-anticoagulant therapy during the past 6 years. The in-hospital mortality rate from embolization was 5 percent. Recurrent embolization was documented in only two patients (3 percent). Three patients (5 percent) required caval ligation because of a profound heparin sensitivity, peptic ulcer bleeding, and recurrent embolization while adequately anticoagulated. The study suggests that adequate anticoagulation is sufficient therapy for most patients and is associated with a low incidence of recurrent embolism. In view of the significant mortality rate reported following caval interruption and especially of the associated long-term venous sequelae, it is concluded that inferior vena caval interruption is seldom indicated in the management of pulmonary embolism and should be performed only when firm indications are present.