Primitive neuroectodermal tumours (PNETs) occurring directly from the lung parenchyma without involvement of the chest wall or pleura are particularly unusual. We describe a 16-year-old male who presented with severe chest and back pain following a fall during high jump competition. Incidental finding of an opacity at the right lung upper lobe was seen on his chest radiograph. Computed tomography of the thorax demonstrated a lobulated hypodense lesion in the anterior segment of right upper lobe and subsequent biopsy confirmed the diagnosis of Ewing Sarcoma/ PNET following histologic and immunohistochemical examination. Whole-body positron emission computed to- mography/computed tomography (PET/CT) revealed mild, homogenous F18-fluorodeoxyglucose (FDG) uptake in the lung lesion with no evidence of metastasis. He eventually underwent right thoracotomy and right upper lobectomy. Indeed, F18-FDG PET/CT is a valuable imaging method in demonstrating active focus of glucose metabolism in lung parenchymal lesion, for preoperative evaluation and as baseline scan for patient’s monitoring.