Primary tumors of the heart are rare. The majority of these tumors are benign, with myxomas located in the left atrium being the most common form. Almost all malignant tumors are sarcomas and occur preferentially in the right side of the heart. Malignant tumors are also described in the left atrium. Large left atrial myxoma size was closely related with constitutional symptoms, congestive heart failure, with syncope and auscultatory findings suggestive of mitral valve disease, whereas smaller myxoma size and irregular surface were associated with embolization. We present the revelation of an asymptomatic left atrial myxoma in a 64-year-old Italian woman during an acute myocardial infarction.