Intracardiac thrombosis is an exceptional complication of Behçet's disease. The management of this involvement is difficult due to the risk of recurrence. We present the case of a young man admitted to our hospital for intermittent fever. The microbiologic investigations did not show any causative germ. We discovered a right ventricle thrombus on echocardiography. We confirmed the diagnosis of pulmonary embolism on CT angiogram. The patient developed oral and genital ulcerations which were consistent with Behçet's syndrome. The thrombus had disappeared after treatment with anticoagulant, corticosteroid and immunosuppressors. Intracardiac thrombosis can reveal Behçet's disease. An exhaustive examination and close monitoring should be performed in order to reveal pathognomonic signs as soon as possible and to promptly start the appropriate treatment.