The heterogeneity of prostate cancer has made imaging modalities of crucial importance in this disease. Accurate diagnosis and staging of the volume and extent of disease, especially in advanced and metastatic prostate cancer, can help to tailor the timing and modalities of treatment. While MRI has been effective in the detection of significant prostate cancer, its use in the identification and quantification of extraprostatic disease is limited. This gap is now being filled by PSMA PET. PSMA PET scans have now been shown to have a role in all stages in the prostate cancer journey. Emerging evidence has shown its promise in primary staging, restaging and theranostics. In this paper, we review the evidence for the use of PSMA PET in the various stages of prostate cancer, from initial diagnosis to advanced metastatic disease where other systemic treatments have failed.