Primary heart neoplasms occur in 0.002-0.3% of autopsies: 30% are myxomas and 20-30% are malignancies, almost always sarcomas. Cardiac metastases are 10 to 40 times more frequent than primary heart cancer. We describe a case of a left atrial sarcoma erroneously diagnosed as myxomas preoperatively. Standard surgical indication for resection of cardiac myxomas is based on echocardiography. Because of the severity of cardiac malignant lesions than can mimic atrial myxomas at echocardiography, through preoperative investigation should be accomplished, best by magnetic resonance imaging. In case of suspected malignancy, total body computed tomography should be performed to avoid unnecessary cardiac operations in case of disseminated cancer. To date the only good medium and long-term results in the therapeutic management of heart sarcomas have been achieved by transplantation: the probable explanation is that criteria of surgical radicality should be those followed for soft tissue tumors located elsewhere in the organism.