A 45 year-old asymptomatic man was admitted to preoperative cardiovascular evaluation for noncardiac surgery. Physical examination and ECG were normal. Transthoracic echocardiography showed a 17 x 35 mm suspicious hyperechoic mass in the interventricular septum. Multi-slice computed tomography (MSCT) was used. Volume rendered image and an axial maximal intensity projection image demonstrated a mass with a density consistent with fat tissue ( - 78 HU). The MSCT findings were diagnostic of a benign lipoma. Thus, this mass was noninvasively diagnosed as cardiac lipoma. Neither life-threatening arrhythmia on Holter monitoring nor myocardial ischemia on exercise scintigraphy was observed.Transthoracic echocardiography is usually the initial diagnostic test in patients with a suspected cardiac mass. However, its sensitivity for differentiating tissue characteristics is limited. MSCT allow for detailed delineation of intra and pericardiac masses. In conclusion, we demonstrated the value of cardiac MSCT to diagnose an interventricular lipoma.