Corticobasal syndrome is the most common phenotype of corticobasal degeneration (CBD). F-FP-CIT PET and MRI are not helpful in distinguishing CBD from idiopathic Parkinson disease. Dual-phase F-FP-CIT PET is a recently developed imaging that shows regional cerebral perfusion in the early phase and dopamine transporter density in the late phase. We investigated the usefulness of dual-phase F-FP-CIT PET imaging in 3 patients with corticobasal syndrome. This image highlights that the early phases of F-FP-CIT PET may reflect regional cerebral perfusion with a pattern very similar to that of regional glucose metabolism in CBD.