This review covers published literature describing the synthesis of labeled carbohydrates for use in molecular imaging, with a particular focus on the use of nuclear techniques (PET, SPECT). Recent advances in the radiosynthesis of [18F]FDG (electrophilic vs. nucleophilic radiofluorinations), a PET radiotracer based on glucose and the most widely PET tracer currently in use for cancer and inflammatory disease diagnosis, is considered. The powerful impact of [18F]FDG in the clinic has prompted intensive research efforts into glucose-based radiotracers for PET and SPECT imaging. These achievements are also reviewed, along with the use of glycopeptides for nuclear molecular imaging. Finally, recent work on the radionuclide labeling of nucleosides and glycoconjugates is discussed.