Infective endocarditis and infection of cardiac devices are conditions characterized by high morbidity and mortality, thus requiring a prompt diagnosis. Advanced imaging modalities are often required in the management of infectious endocarditis according to guidelines. The aim of this review is to collect and describe evidence-based knowledge about the diagnostic role and clinical usefulness of [ ¹⁸ F]FDG PET/CT in endocarditis and cardiac device infections based on published systematic reviews and meta-analyses on this topic and on recent guidelines. [ ¹⁸ F]FDG PET/CT is recommended only in selected cases. This imaging method has good diagnostic accuracy in detecting prosthetic valve endocarditis and cardiac device infection. Furthermore, it can identify extra-cardiac infectious foci changing the clinical management in a significant percentage of cases.