Primary pulmonary Schwannomas are extremely rare and their radiological manifestations are varied. We presented a 42-year-old female patient with a huge benign Schwannoma, 8 cm at its greatest dimension, arising in the left upper lobe of the lung. This benign tumor showed an increased fluorodeoxyglucose (FDG) uptake in the positron emission tomography (PET)/computed tomography (CT) imaging. The patient underwent a lobectomy of the diseased lung with a complete removal of the tumor. She remained asymptomatic after a 14-month follow-up. In this report, we focused the discussion on the radiological findings so as to improve the diagnosis of this rare disease.