Background <p>Immunotherapy has become a promising therapeutic strategy for various solid tumors because it harnesses the immune system to target malignant cells. However, prostate cancer (PCa) remains largely resistant to immune-mediated therapies and is often described as a “cold” tumor, characterized by limited immune cell infiltration and pronounced immunosuppressive signaling in its tumor microenvironment. These biological characteristics substantially limit the clinical efficacy of immunotherapeutic approaches in PCa.</p> Main body <p>This review provides a comprehensive summary of current advances and persisting challenges in the field of PCa immunotherapy. It provides an updated overview of therapeutic vaccines targeting tumor-associated antigens, the clinical application and limitations of immune checkpoint inhibitors, and emerging cellular therapies such as chimeric antigen receptor T cell (CAR-T) therapy and bispecific antibodies. The review also discusses emerging combination strategies that integrate immunotherapy with androgen receptor-targeted therapies and novel immune modulators. Furthermore, it highlights the critical role of the tumor microenvironment and molecular biomarkers in predicting therapeutic response and optimizing patient selection.</p> Conclusions <p>Although the immunosuppressive nature of PCa presents substantial therapeutic challenges, recent advances in immunotherapy and combinatorial strategies has demonstrated promising signs of efficacy. Continued translational research aimed at overcoming immune resistance, refining patient selection, and developing rational immunotherapy-based combinations may ultimately transform the therapeutic landscape of PCa.</p>