Parry-Romberg syndrome is a rare disorder characterized by a progressive facial hemiatrophy of the skin, subcutaneous tissue, musculature, bone, and cartilage. It is often associated with neurological symptoms such as trigeminal neuropathy, paresthesia of the face, migraine, and seizures and can be paired with ocular problems and ipsilateral progressive body atrophy. Here, we present a young woman with progressive facial hemiatrophy, who was referred for FDG-PET/CT. Hypometabolism was observed in the left cingulate and postcentral gyrus, left cerebellum, and right basal ganglia. Hypometabolism may be observed before anatomical changes and therefore facilitate early diagnosis.