This paper aims to describe the usefulness of transthoracic echocardiography in the follow-up of recurrent nonbacterial thrombotic endocarditis (NBTE) associated with neoplastic conditions. A 60-year-old woman with advanced uterine cancer developed recurrent areas of aseptic vegetation on the mitral valve along with cerebral, renal and splenic embolisms. Echocardiographic assessments revealed vegetation and thrombotic events on three occasions. In this case, transthoracic echocardiography was effective in following the decreased frequency of attachment of the NBTE vegetation to the mitral valve and reductions in the size of the area of vegetation following treatment with unfractionated heparin infusion, hysterectomy and chemotherapy.