Non-bacterial thrombotic endocarditis (NBTE), also known as non-infective endocarditis, is a rare condition characterised by formation of sterile fibrin and platelet depositions on heart valves. NBTE is commonly seen in advanced malignancies, auto-immune disorders and conditions associated with a hypercoagulable state. Patients are often asymptomatic. Clinical manifestations are a result of a multifocal systemic embolisms in brain, spleen, kidney, skin or extremities. Laboratory tests and blood cultures should be taken in the work-up to differentiate with an infectious endocarditis. Furthermore, a transthoracic or transoesophageal echocardiography should be performed. Often diagnosis can only be based on clinical signs and symptoms, without confirmation by imaging. Therapy includes anticoagulation with low molecular weight heparin or non-vitamin K antagonists, treating the underlying disease and surgical intervention. In this article, we present two cases and argument to include NBTE in the differential diagnoses when systemic embolisms occur in patients with malignancies of auto-immune disorders.