A significant number of meta-analyses reporting data on the diagnostic performance of positron emission tomography (PET) in prostate cancer (PCa) is currently available in the literature. In particular, different PET radiopharmaceuticals were used for this purpose. The aim of this review is to summarize information retrieved by published meta-analyses on this topic. The first step included a systematic search of the literature (last search date: June 2020), screening two databases (PubMed/MEDLINE and Cochrane Library). This combination of key words was used: (A) “PET” OR “positron emission tomography” AND (B) “prostate” OR “prostatic” AND (C) meta-analysis. Only meta-analyses on Positron Emission Tomography/Computed Tomography (PET/CT) or Positron Emission Tomography/Magnetic Resonance (PET/MR) in PCa were selected. We have summarized the diagnostic performance of PET imaging in PCa, taking into account 39 meta-analyses published in the literature. Evidence-based data showed the good diagnostic performance of PET/CT with several radiopharmaceuticals, including prostate-specific membrane antigen (PSMA)-targeted agents, radiolabeled choline, fluciclovine, and fluoride in restaging and staging settings. Less evidence-based data were available for PET/MR with different radiotracers. More prospective multicentric studies and cost-effectiveness analyses are warranted.