Cancer treatment modalities are still at the forefront of biomedical research efforts due to the huge socioeconomic impact of this disease. Light has proven itself powerful as either a diagnostic or a therapeutic tool, especially with the recent advances in laser light sources, light-emitting diodes (LEDs), and other optical components. Immunotherapy is one of the most rapidly developing fields in cancer research. The use of light to induce photothermal or photochemical effects in tumor tissue can also induce a potent immune response, which can then attack primary as well as metastatic tumors. In the case of photothermal effects, the process is called in situ cancer vaccination (inCVAX) and with the aid of an immunostimulant like glycated chitosan, tumor antigens are liberated and taken up by mature DCs (DCs) that in turn present them to naïve T-cells and B-cells to induce not only tumor destruction, but also a systemic immune response. On the other hand, photodynamic therapy (PDT) involves the light-mediated excitation of photosensitizer molecules to an excited triplet state, which undergo photochemical reactions to produce free radicals and reactive oxygen species (ROS). These ROS can destroy cancer cells and liberate tumor antigens that could also activate innate and humoral immune responses. In this chapter, we discuss these two methods as examples of light-based treatmentLight-based treatment for cancer approaches for cancer, and how they could be combined with other conventional cancer therapies to improve cure rates and improve patient quality of life.