We report the case of a patient complaining of intermittent fever for two years. After three episodes which were well controlled in a few days by antibiotic therapy, in October 2004 she came to our observation for the reappearance of fever. Our findings included high levels of inflammation indexes, a left atrial power at ECG, and an enlargement of the heart at chest radiography. Finally, transthoracic echocardiography showed the presence of a mass in the left atrium, subsequently identified as a myxoma after its surgical excision. To date the patient has reported no new episodes of fever. We recommend careful examination of all patients with unexplained fever so to avoid failure to identify rare but potentially fatal causes of fever (e.g.: myxoma).