Prostate cancer treatment is currently based on surgical removal, radiotherapy, and hormone therapy. In recent years, another therapeutic method has emerged-immunological treatment. Immunotherapy modulates and strengthens one's immune responses against cancer. Neoplastic cells naturally escape from the control of the immune system, and the main goal of immune therapy is to bring the control back. Satisfying outcomes after treatment of advanced melanoma and lung cancer suggest a great potential of immunotherapy as an approach for other tumors' treatment, especially in patients primarily introduced to palliative care. After initial clinical trials, immunotherapy seems to have different side effects than chemotherapy. Prostate cancer was the first neoplasm in which a specific vaccine significantly improved survival. There is a tremendous potential for synergistic combinations of immunotherapy with conventional cancer treatments. A combination of several drugs or methods can be a key in radical treatment of metastatic prostate cancer as demonstrated by preliminary studies.