The entity of NBTE is reviewed in this article. Historic aspects, epidemiology, and pathogenesis are discussed. The clinicopathologic findings are emphasized as well as the potential for antemortem diagnosis and therapy. NBTE is diagnosed infrequently before death. Clinical suspicion is aroused in patients with an underlying process such as malignancy, DIC, or a spectrum of other diseases and evidence of pulmonary and/or systemic embolization. Systemic infection must be excluded. Two-dimensional echocardiography can be utilized to confirm the diagnosis. Anticoagulation therapy with heparin may prevent embolization.