Osteosarcoma (OS) is a malignant tumor of mesenchymal origin and composed of osteoid tissue or immature bone production. OS of the skull is exceedingly rare and devastating tumors. The overall prevalence of primary craniofacial OS is around 2-9% in published series, while the prevalence of pure cranial localization is 1-2%. It usually develops secondary to preexisting bone diseases or after the radiation therapy. Local recurrence rates are 26-69% and five-year survival rate is 25-37%. Amongst primary craniofacial OS, skull lesions appear the have the worst prognosis. In this report, the clinical, radiologic, pathological features, recommended treatment and prognosis of a 26-year-old female patient diagnosed with primary calvarial osteosarcoma has been discussed.