A 57-year-old male with lung cancer was referred for a F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scan for staging purposes. The maximum intensity projection image unexpectedly showed the gauntletlike distribution of intense F-18 FDG uptake in the left forearm and hand. Transaxial PET/CT fusion images of left antecubital fossa indicated that the injection reached the left brachial artery against the left humerus. The appearance of these imaging characteristics led to a manifestation of the hot gauntlet sign resulting from an accidental intra-arterial F-18 FDG administration in the antecubital region.