Primary sarcomas of the heart are extremely rare, whereas secondary cardiac involvement with malignancy is relatively common, especially in the setting of widespread metastatic disease. Patients may present acutely with catastrophic hemodynamic instability, but presentation is more commonly nonspecific. The symptoms of primary cardiac sarcomas are often misattributed to more common conditions, and secondary cardiac involvement may be overlooked in the constellation of symptoms associated with widespread metastases. Initial diagnosis of cardiac malignancy is best made with echocardiography, but a more complete assessment of local and regional disease extent with CT and MRI is required when curative management is contemplated. Early diagnosis and radical excision are essential to long-term survival for primary cardiac sarcoma and can lead to long-term survival, although this is rarely accomplished and overall results are very disappointing. Neoadjuvant chemotherapy and radiotherapy have a limited role in primary management, but can be beneficial and should be considered for selected cases. Orthotopic cardiac transplantation is a controversial treatment for primary cardiac sarcoma, but has been associated with prolonged survival in selected cases. Secondary cardiac involvement with malignancy usually occurs at the terminal phase of a prolonged disease course, and palliative chemotherapy, radiotherapy, and surgery can provide temporary symptomatic relief. In the specific instance where secondary cardiac involvement leads to the initial diagnosis of malignancy, or is the first evidence of small-volume metastatic recurrence, aggressive surgical management may result in long-term survival, provided that all gross tumor can be excised. Management is always complex, and patients with malignant cardiac involvement should be referred to centers of specialized expertise for multidisciplinary assessment and treatment whenever possible.