Background Cardiac myxomas rarely occur in children or adolescents. In addition, it is even more rare for the adolescent patient to present with neurological symptoms only. Early diagnosis is difficult because the symptoms of left atrial myxoma are frequently nonspecific. If delayed or left undiagnosed, severe and fatal complications, such as systemic embolism, heart failure, and pulmonary hypertension, may occur. Case Report A 13-year-old girl was admitted to our resuscitation room because of loss of consciousness for the preceding 2 h; she had a longstanding history of headache and dizziness for the previous 18 months. Repeated investigations at her local hospital did not reveal any abnormalities. During this admission, routine chest x-ray study found an abnormal bulge of a segment of the pulmonary artery and elevated cardiac enzymes. Emergency bedside echocardiography was performed and revealed a myxoma in the left atria. Subsequent computed tomography head revealed cardiogenic cerebral embolism. When her condition was stable, the patient was taken to the operating room, where a tumorectomy was performed successfully. The patient was then treated with oral anticoagulants and an uneventful recovery was made. Why Should an Emergency Physician Be Aware of This? In order to avoid delayed diagnosis and treatment of its potentially fatal complications, it is important for the emergency clinician to have a high level of suspicion for a cardiac myxoma when attending to young patients that present with syncope. We therefore recommend that, as routine practice, bedside echocardiography to be carried in the emergency department for young patients that present with syncope.