Leiomyosarcoma of the mediastinum is sufficiently rare; therefore therapeutic approaches are not well defined. Current therapy primarily rests with the thoracic surgeon. We report a single case of a large leiomyosarcoma of the mediastinum invading the heart and right lung. Our diagnostic and therapeutic approach to this patient is presented and the pertinent literature is reviewed. We conclude that little advancement has been made with regard to adjuvant therapies for leiomyosarcoma of the mediastinum, and the only opportunity for cure remains with full surgical extirpation.