Osteosarcoma is classically defined as a high-grade spindle-shaped neoplasm with malignant cells that produce osteoid. It is the most common primary malignant bone tumor in children and young adults. It is <1% of all cancers diagnosed, approximately 3.4% of all childhood cancers. The age-adjusted incidence of osteosarcoma is bimodal, with an initial peak in adolescence and then a second peak in patients over 60 years of age. Osteosarcoma is divided into two main groups. In most of the osteosarcomas, the etiological agent cannot be determined and it is called primary osteosarcoma. Osteosarcoma, which develops due to etiologies such as Paget’s disease, radiotherapy or osteonecrosis, is called seconder osteosarcoma. Osteosarcomas are most commonly located in the appendicular skeleton. The most common settlement here is the knee circumference. The distal femur and proximal tibia are the most common locations in the knee. A multidisciplinary approach is indicated in the management of osteosarcoma. The treatment is multimodal, including systemic chemotherapy and local therapy. In this section, we will outline the current standard of care for the systemic and surgical approach to osteosarcoma treatment, as well as an overview of current studies.