Chloroma (granulocytic sarcoma) indicates an extramedullary leukemic cell collection. It often develops in the course of, or as a presenting sign of leukemia. Cardiac chloroma is uncommon and rarely detected as a mass. We report the first case of cardiac chloroma in a patient with acute lymphocytic leukemia in Korea. A 73-year-old man was admitted because of exertional dyspnea, orthopnea and generalized weakness. Thrombocytopenia and immature leukocytes were detected in the peripheral blood. An X-ray film of the chest showed mild cardiome-galy and bilateral pleural effusion. Transthoracic and transesophageal echocardiography showed a low echogenic mass at the lateral wall of the right ventricle. The size of the mass was about 6x4 cm. MRI of the chest showed right ventricular mass with slightly increased inhomogeneous signal intensity. Bone marrow aspiration and biopsy confirmed that he had a L3 FAB subtype of acute lymphocytic leukemia. Induction chemotherapy with vincristine, prednisolone, daunorubicin resulted in hematologic complete remission. At 6 weeks after the induction chemotherapy, transesophageal echocardiography demonstrated disappearance of the right ventricular mass which suggested that it was a cardiac chloroma complicating acute lymphocytic leukemia.