Osteosarcoma is the most common primary bone malignancy in children and adolescents. Because the incidence of osteosarcoma is low and the disease occurs in physically active patients, it may be misdiagnosed as a more benign condition, thus leading to late diagnosis. This article describes the disease's most frequent presenting complaints and initial radiographic findings, as well as its risk factors and common misdiagnoses. Clinicians should consider osteosarcoma in young patients with persistent bone pain, especially pain with weight-bearing.