A rare case of metastatic soft tissue sarcoma (STS) involving the endocardium of the left ventricle of the heart is described. A 57-year-old man with a previously resected synovial sarcoma of the anterior abdominal wall presented 5 years later with an acute ischaemic arm resulting from tumour embolus. The treatment and outcome of the patient are outlined. Metastatic STS cardiac involvement and management of this complication are reviewed.