We report a rare case of lipoma arising from the right ventricle. A 66-year-old woman was admitted to our hospital for exertional chest pain and fatigability. She was diagnosed of mild aortic stenosis and regurgitation (ASR), mild mitral regurgitation (MR), and asymptomatic cardiac tumor in the right ventricle about two years previously, for which she had been followed up at other local hospital. A recheck transthoracic echocardiography revealed moderate MR. No evidence of deterioration of ASR and cardiac lipoma were detected. The patient underwent mitral annuloplasty and replacement of aortic valve, plus resection of the right ventricle tumor through the tricuspid valve. Pathological examination of the resected tumor showed mature adipose tissue infiltrated into normal cardiac muscle without atypical cells, which suggested intramyocardial lipoma. Postoperative course was uneventful. Fourteen months after the operation, the patient remains asymptomatic and regular echocardiographic checkup demonstrates no tumor recurrence or residual MR.