High-grade surface osteosarcoma is a high-grade bone-forming neoplasm which arises on the surface of the bone. It has a male predominance. Peak incidence is in the second decade of life. A majority of patients are in the second and third decades of life. Radiologically, the lesion presents a large mass with a broad-based attachment to the underlying bone. There is a dense to moderate mineralization with a fluffy immature appearance. There is partial cortical destruction and periosteal new bone. Histologically, it is identical to conventional osteosarcoma (osteoblastic, chondroblastic, fibroblastic subtypes). All tumors are high grade. Treatment consists of neoadjuvant chemotherapy followed by surgical resection with a wide margin.