Osteosarcoma is a primary malignant tumour that accounts for less than 1% of cancers diagnosed annually in the United States and 3% of all cancers in paediatric patients. Surgical treatment and adjuvant chemotherapy are essential to improve short- and long-term survival. In this report, we present the case of an 11-month-old female patient referred to the first level of care for a suspected tumour in the left orbit, who underwent biopsy and tumour resection surgery by the maxillofacial surgery service and underwent adjuvant chemotherapy in a specialised centre. Timely detection of cancer in the paediatric population, as well as multidisciplinary management and close surveillance, improves the survival and quality of life of patients.