Nonbacterial thrombotic endocarditis (NBTE), formerly known as marantic endocarditis, is a potentially overlooked condition that involves the formation of sterile, fibrin vegetations on heart valve leaflets. Often confused with classic infective endocarditis during its early stages, NBTE can lead to valvular dysfunction, heart failure, and systemic embolization when unchecked. The pathogenesis is not entirely clear but involves a preexisting hypercoagulable state. Diagnosis requires ruling out infection and establishing the presence of valvular vegetations using echocardiography. Therapy for NBTE includes treating the underlying disease, systemic anticoagulation and surgical intervention.