Fatty masses of the heart are relatively uncommon. This report is about an extremely rare case of cardiac lipomatosis that implicates both ventricles and inter-atrial septum. The patient was a 27-year-old female who was accidentally diagnosed during a routine physical examination. Trans-thoracic echocardiography (TTE) discovered a large homogenous bi-lobed, non-encapsulated echogenic mass. Magnetic resonance imaging (MRI) showed soft tissue abnormal enhancement in the anterior left base of the heart and sub-aortic outflow tract. A trans-jugular echomyocardial biopsy was done because of a lack of a definite diagnosis by non-invasive techniques. Pathological study showed benign fatty infiltration suggestive for benign lipomatous hypertrophy.