Primary malignant sternal tumours are very rare. The most common malignant sternal tumour is a chondrosarcoma. Until now, controversies in the management of malignant sternal tumours were mainly caused by limited clinical experience. However, treatment of malignant sternal tumours should not differ from that of chest wall malignancies. In this paper a 74-year-old man with a kyphoscoliosis and an osteosarcoma of the sternum is described who received combined treatment modalities, consisting of surgical resection and reconstruction with a myocutaneous flap, followed by external beam radiotherapy. This treatment strategy is discussed.