An 80-year-old male with a previous history of thymoma and kidney cancer underwent a 18F fluorodeoxyglucose (FDG) positron emission tomography (PET)/contrast-enhanced computed tomography (CT) scan: two pulmonary nodules were discovered, both characterized by an increased glucose uptake. Of them, only one showed mild contrast enhancement. Both nodules were surgically resected: the first nodule was a benign meningioma and the second one was a malignant meningioma. This case study shows that malignancy of meningioma in the lung is not correlated with 18F FDG uptake and the contrast enhancement, thus suggesting that PET/CT may represent a suboptimal imaging modality for the evaluation of these lesions.