Cardiac lipomas, which are benign nonmyxomatous neoplasms of the heart, are rare and among those least often encountered. Because they normally cause no symptoms, diagnosis is often purely accidental. We report the case of a 24-year-old woman who presented with palpitations of recent onset and was found to have a lipoma attached to the left side of the interventricular septum (IVS). Transthoracic and transesophageal echocardiograms were performed and showed a mass in the left side of the IVS. During successful surgical excision of the mass, intraoperative histologic diagnosis showed the tumor was lipoma. Our review of the English literature revealed that our case is only the seventh of removal of lipoma in the IVS. The postoperative course was uneventful, and an echocardiogram taken 6 months after the operation showed no evidence of enlargement of the tumor tissue.