Disseminated intravascular coagulation (DIC) can be defined as evidence of activation of the coagulation mechanism resulting in proteolysis of fibrinogen by thrombin and plasmin and an acute thrombocytopenia. The association of pulmonary embolism (PE) with DIC has recently been reported but in reviewing recent textbooks of hematology, there is no mention of PE as a cause of DIC. Clinicians need to be made aware of this association since it affects the patient who is thought to be autoanticoagulated as well as the patient who has DIC of unknown cause. PE needs to be included in the differential diagnosis of an autoanticoagulated state and in DIC of unknown etiology. In both instances the recommended treatment is full-dose intravenous heparin therapy.