Prostate-specific membrane antigen (PSMA) is an integral, non-shed membrane glycoprotein that is highly expressed on prostate epithelial cells and strongly upregulated in prostate cancer (PCa). Prostatic neoplastic transformation results in the transfer of PSMA from the apical membrane to the luminal surface of the ducts. However, the role of PSMA in tumor angiogenesis and carcinogenesis is poorly understood. PSMA is characterized by folate hydrolase and carboxypeptidase activity and internalization function, and its levels are directly correlated to androgen independence, metastasis and PCa progression. As largely substantiated by preclinical and clinical findings, PSMA could represent a promising target for Positron Emission Tomography (PET) radiopharmaceuticals for PCa imaging. Furthermore, PSMA could prove an important target for the development of new therapeutic approaches, including PSMA-based aptamers, peptides, antibody-drug conjugated therapy, as well as radiotherapy and immunotherapy. This review will summarize the role of PSMA in PCa development and progression and its potential role in the diagnosis and treatment of patients with initial and advanced PCa.