Photodynamic therapy (PDT) is a promising treatment that modulates both the innate and adaptive immune systems, showing potential in cancer therapy. Recent studies indicate that PDT can recruit and activate immune cells such as neutrophils, macrophages, and dendritic cells at the treatment site. Clinical trials are exploring PDT's effectiveness in various cancers and its impact on immune responses. Combining PDT with immunotherapy has shown promise in enhancing antitumor immune responses. PDT can induce immunogenic cell death, leading to the release of damage-associated molecular patterns and activating the immune system. Photosensitizers like 5-ALA and Indocyanine Green (ICG) have been studied for their effects on immune cells and their potential in cancer treatment. Clinical trials are ongoing to evaluate the impact of PDT on immune responses in cancer patients. The review highlights the role of PDT in modulating immune cells, enhancing immune responses, and combining with immunotherapy for improved outcomes. The study also discusses the potential of PDT in combination with immune adjuvants and vaccines, as well as its role in targeting immune checkpoints. Despite advancements, further research is needed to fully understand the mechanisms of PDT's impact on the immune system in cancer treatment. The review summarizes current findings and ongoing clinical trials to provide insights into the potential of PDT in cancer immunotherapy.Photodynamic therapy (PDT) is a promising treatment that modulates both the innate and adaptive immune systems, showing potential in cancer therapy. Recent studies indicate that PDT can recruit and activate immune cells such as neutrophils, macrophages, and dendritic cells at the treatment site. Clinical trials are exploring PDT's effectiveness in various cancers and its impact on immune responses. Combining PDT with immunotherapy has shown promise in enhancing antitumor immune responses. PDT can induce immunogenic cell death, leading to the release of damage-associated molecular patterns and activating the immune system. Photosensitizers like 5-ALA and Indocyanine Green (ICG) have been studied for their effects on immune cells and their potential in cancer treatment. Clinical trials are ongoing to evaluate the impact of PDT on immune responses in cancer patients. The review highlights the role of PDT in modulating immune cells, enhancing immune responses, and combining with immunotherapy for improved outcomes. The study also discusses the potential of PDT in combination with immune adjuvants and vaccines, as well as its role in targeting immune checkpoints. Despite advancements, further research is needed to fully understand the mechanisms of PDT's impact on the immune system in cancer treatment. The review summarizes current findings and ongoing clinical trials to provide insights into the potential of PDT in cancer immunotherapy.