The patient was a 39-year-old man hospitalized due to the presence of a cardiac mass and heart failure. Emergency tumor resection and mitral valve replacement were performed. The pathological findings of the tumor led to a diagnosis of cardiac leiomyosarcoma. After the operation, multiple metastases were found. The patient underwent three courses of chemotherapies: adriamycin, ifosfamide, dacarbazine, and mesna (MAID therapy), gemcitabine plus docetaxel, and sunitinib. During MAID therapy, the patient underwent resection of gastrointestinal metastases twice due to gastrointestinal hemorrhaging. Although he died 27 months after the initial treatment, use of multimodal therapy was effective in achieving a longer survival for the patient.