Background.: Non-bacterial thrombotic endocarditis is a severe complication of cancer, rarely reported in gynecologic tumors. However, it can be inaugural and lead to complex diagnostic pathways. Case.: A 40-year-old woman presented with a stroke, related to an endocarditis. The valvular vegetation was surgically removed, and a malignant node was resected. A PET-scan led to the diagnosis of a myometrial tumor, which was found to be a primitive neuroectodermal tumor (PNET). The patient underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy, and systemic chemotherapy which allowed a complete remission of tumoral and cardio-vascular symptoms. Conclusion.: To our knowledge, this is the first case report of a PNET of the myometrium revealed by cardio-vascular symptoms. © 2007.