Cerebrovascular events occur frequently in patients who succumb to cancer, and nonbacterial thrombotic endocarditis (NBTE) is a frequent postmortem finding in these patients. Despite the excellent diagnostic accuracy of transesophageal echocardiography (TEE) for cardiac sources of cerebral embolism, however, the prevalence of NBTE and other cardioembolic sources in patients with cancer and cerebral ischemia has not been investigated using this modality. This study examined the frequency of cardioembolic findings in consecutive patients with cancer referred to our institution for TEE evaluation of cerebrovascular events. The study cohort comprised 51 patients, of whom 18% had marantic vegetations, and 47% and 55% of whom had definite and definite or probable cardiac sources of embolism, respectively. The present study documents, for the first time, a high frequency of marantic endocarditis and other cardioembolic sources in patients with cancer and cerebrovascular events selected for TEE. This finding has important implications for evaluation and management in this patient population.