Although 18F-fluoro-deoxy-glucose (FDG) positron emission tomography (PET) has been widely validated and extensively used in the latest years in clinical practice, interpretation of PET/CT images can be affected by several pitfalls. We here present a case of intense lung uptake in a patient without a corresponding finding on CT images, probably due to a microembolism produced during the injection process and located in small vascular structures of the lung parenchyma.