Osteosarcoma is the most common bone malignancy in children. Osteosarcoma prevalence of 20% of all primary bone tumors in children. This study aims to determine the prevalence of osteosarcoma patients at Prof. Dr. I G N G Ngoerah Hospital. This was a retrospective study used secondary data collected from solid tumor register in Prof. Dr. I G N G Ngoerah Hospital in January 2016 – June 2022. Data from Prof. Dr. I G N G Ngoerah Hospital in January 2016 – June 2022 showed the prevalence of osteosarcoma in children is 30 cases, which the total cases had a greater prevalence in the male sex 18 (60%) and the age group 5 - 14 years amounted to 16 (53.3 %). In nutritional status, the highest prevalence was in good nutritional status 14 (46.7%), the highest location prevalence was in the tibia 12 (40%). Hematological data showed mean WBC 11.18, Std. deviation 5.37. Mean neutrophil 9.18, Std.deviation 12.15. Mean Hb 11.61, Std. deviation 2.71. Mean Plt 329.81 Std, deviation 129.42. Among amputated patient, 3 patients survive (10%), 4 patients died (13%). Among non-amputated patient, 8 patients survive (26%), 24 patients died (80%). Data on prevalence and characteristics are important as basic data in understanding risk factors and prognosis of osteosarcoma. Early detection, prompted management and selective amputation must be conducted to improve survival of the patients.