We report the case of a 64-year-old man referred for optic ataxia, constructional apraxia, and spatial orientation disorders evolving for 2 months. Benson syndrome (posterior cortical atrophy) was initially suspected. Brain F-FDG PET/CT depicted an asymmetric decreased uptake pattern consistent with Creutzfeldt-Jakob disease. 14-3-3 proteins were detected in the cerebrospinal fluid. Clinical evolution was quickly unfavorable. The patient died 1 month after the PET/CT, and Creutzfeldt-Jakob disease was confirmed on postmortem examination of brain tissue.