Abstract Primary malignant neoplasms of the heart are rare. Cardiac rhabdomyosarcoma is the second most common primary sarcoma. We report a rare case of a 49-year-old woman with a huge biatrial cardiac rhabdomyosarcoma treated by performing surgical resection followed by salvage chemotherapy for local recurrence. Cardiac sarcoma that occupy both atria are extremely rare. Although the prognosis of cardiac rhabdomyosarcoma is dismal, surgical resection should be recommended as a first line therapy to clarify the diagnosis and to relieve symptoms associated with the tumor.