Lipoma in the ventricular septum is very rare. Our review of the English literature revealed that our case is the sixth of removal of lipoma in the ventricular septum. A 60-year-old male was admitted because a mass in the ventricular septum was found incidentally in abdominal CT taken following type B hepatitis. CT scanning of the heart showed 2 cm diameter of tumor in the ventricular septum. The tumor had very low radiodensity, so it was thought to be identical to fat tissue. The tumor was more clearly visualized by MR imaging and the signal intensity was high on the T1-weighted image. The tumor was suspected to be lipoma. The intraoperative histological diagnosis showed the tumor was lipoma. The tumor adhered strictly on the myocardium of the septum, and it was located near the left anterior descending coronary artery. It could not completely resected, in these reasons. Postoperative course was uneventful, and echocardiogram taken 9 months after the operation showed no evidence of enlargement of the residual tumor. It is necessary to follow-up rigidly for the potential of enlargement of the residual tumor.