Diagnosis of cardiac mechanical device or prosthesis valve infection, and more importantly accurate localization of the infection site, such as defibrillator pocket, pacemaker lead, annular or peri-annular valve ring abscesses remain clinically challenging. Inconclusive diagnosis can lead to delayed antibiotic therapy, device extraction or surgical intervention, which may have dire consequences to the patient. Among patients with suspected cardiac mechanical device or prosthetic valve infection, recent publications advocate the use of ¹⁸ F-fluoro-2-deoxyglucose positron emission tomography computed tomography (FDG PET/CT), particularly when anatomy based imaging studies, such as echocardiography or CT, are uncertain or negative. A potential advantage of FDG PET/CT is in its detection of inflammatory cells early in the infection process, before morphologic damages ensue. However, there are many unanswered questions in the literature. There is a need for standardization amongst the various imaging studies, such as dietary preparation, duration and timing of image acquisition, image processing with and without CT attenuation correction, and more importantly image interpretation criteria. The answer for these issues awaits well designed, prospective studies.