An infected vascular graft was identified using a combined positron emission tomography (PET) and computerized tomography (CT) system. The fusion of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) PET and CT images, acquired in a single session, allowed for the precise localization of the abnormal FDG uptake to the vascular graft and led to the correct diagnosis of prosthetic infection. This hybrid modality, which provides precise registration of metabolic and structural imaging data, may enhance the potential use of FDG in the diagnosis and management of infected vascular grafts.