We present a patient with an occult adenocarcinoma which manifested clinically as a confusional syndrome due to multiple cerebral infarctions associated to pericarditis and immunological abnormalities. Neurological involvement was secondary to nonbacterial thromboembolic endocarditis (NBTE) which did not provoke cardiac murmurs nor was detected in type B echocardiogram. Malignant cells were not observed in the pericardial effusion or in the pericardial biopsy (1.5 x 1 cm). The clinical picture mimicked an atypical lupous syndrome. The positive diagnosis was established on necropsy. The cardiovascular complications are not frequent in cancer. NBTE usually shows up clinically as a neurologic syndrome due to multiple cerebral infarctions: the normality of complementary exams and the lack of demonstration of an underlying disease do not rule out its diagnosis. When suspecting an NBTE treatment with heparin should be promptly started.