Pulmonary Sclerosing Pneumocytoma (PSP) is a rare tumour of the lung and is always benign. Diagnosis is made incidentally following chest X-ray or chest CT scan performed for other clinical conditions. We report a case of PSP in a seven-year-old girl who got admitted for evaluation of an anterior mediastinal mass. Clinically, thought of teratoma or other germ cell tumour the mass was excised and sent for histopathological examination. Grossly, we received a pneumonectomy specimen measuring 13x11x8 cm with a nodular firm grey white lesion in the medial aspect of lower and middle lobe measuring 7.5x5.5x5 cm. Macroscopically, pleura was involved and adherent to the lung. Microscopy showed, an ill-defined lesion in the lung with extensive fibrosis and lymphoplasmacytic infiltrate. The lesion was composed of round to oval cells with ill defined cell border, moderate eosinophilic cytoplasm and bland nuclei. A panel of Immunohistochemical (IHC) markers was performed and the lesional cells were positive for Epithelial Membrane Antigen (EMA) and Thyroid Transcription Factor-1 (TTF-1). The prognosis after surgical resection is good and the patient is doing well.