BACKGROUND Primary cardiac tumors are rare forms of cardiac disease. The reported incidence varies between 0.002 and 0.3%; 25% of these tumors are malignant, usually a variant of sarcoma. Malignant fibrous histiocytoma constitutes <3% of primary cardiac tumors. METHODS We review the case of a 53-year-old female who presented with congestive heart failure and pleural effusion. Transthoracic echocardiography and chest computed tomography revealed cardiac tumor involving the left atrium. Tumor was excised surgically and histologically proven to be a malignant fibrous histiocytoma, primarily confined to the heart. During the immediate postoperative evolution, the patient presented left pleural effusion for 2 weeks. The patient was referred to Oncology Service for complementary treatment. CONCLUSIONS Malignant fibrous histiocytoma is a rare tumor and, in this case, prognosis is reserved.