The inherent inability of ultrasonography (US) to penetrate cortical bone is a major limitation preventing its use in the evaluation of bone tumours. However, once the bone cortex is breached with a production of a subperiosteal or extra-osseous mass, bone tumours become accessible to US evaluation. Additionally, lesions arising from the bone surface can be imaged with US. In this chapter, the US features of bone tumours are highlighted. Furthermore, the role of US in guiding percutaneous needle biopsy of bone tumours is discussed, as US-guided biopsy is of great value when the cortex is destructed with or without an associated extra-osseous mass.