Clear cell sarcoma is a rare soft tissue tumor. Cardiac metastasis of clear cell sarcoma is seen even rarely. A 34-year-old female patient was admitted to our hospital with the complaints of pain and swelling on the posterior aspect of her right knee. She was operated and the popliteal mass was removed with clean surgical borders. Fourteen months following diagnosis, the patient applied to our clinic with a metastatic mass of 47x33 mm size at the junction of the right atrium and right ventricle. A pericardial window was opened and pericardial resection was made through left anterolateral thoracotomy. Biopsy of the lesions in the right ventricle showed similar findings with the popliteal tumor and was reported as clear cell carcinoma metastasis. The patient was re-hospitalized in the second month of the follow-up. Cardiac arrest occurred during the supportive therapy. Emergent median sternotomy was performed. Tumor mass had grown extremely large. The patient died. In this article, metastasis of clear cell sarcoma to the heart was reported for the first time. The involvement of heart by clear cell sarcoma was aggressive. Although pericardial resection and opening a pericardial window provided temporary relief, the prognosis was fatal due to rapid growth of the tumor.