A 79-year-old man found to have a pulmonary nodule and pleural effusion on CT went on to have an 18 F-FDG PET/CT scan. The lung abnormality did not show FDG uptake and appeared benign. However, PET/CT detected moderately increased FDG uptake associated with a left atrial appendage closure device inserted 11 months prior to the PET/CT. Infection of a left atrial closure device has previously been demonstrated with FDG PET/CT. This case, in the absence of infection, with normal serum inflammatory markers, highlights that left atrial closure devices, in common with other foreign bodies/devices, may demonstrate significant, incidental FDG uptake.