Fluorine-18-fluorodeoxyglucose (F-18-FDG) is the most used positron emitter radiopharmaceutical worldwide. This glucose analogue allows to study the glucose metabolism which is often increased in many tumors. Nowadays the diagnostic performance of positron emission tomography/computed tomography (PET/CT) using F-18-FDG in different tumors is well known. On the other hand, to date, there is an increasing interest for the use of PET tracers other than F-18-FDG in oncology, because they allow to study different metabolic pathways or receptor expression. The aim of this review is to summarize the scientific literature about the diagnostic performance of PET/CT using tracers other than F-18-FDG in oncology through an evidence-based approach. In particular, the results of meta-analyses (representing the highest level of evidence) on the diagnostic performance of PET tracers other than F-18-FDG in different tumors are described. Furthermore, recommendations for the use of different PET tracers in oncology are provided based on existing literature data.