Oral cancer is a major public health problem worldwide and is among the ten most common cancers. Despite the advances in research and treatment, oral cancer is still one of the major challenges in medical science. Common treatments for this cancer include surgery, radiotherapy, and chemotherapy, as well as adjuvant photodynamic therapy (PDT). The aim of this study was to evaluate oral cancer and its treatment methods with an emphasis on the use of adjuvant PDT. The present study is a review performed by searching the articles published in the past 20 years (2000-2020) in Elsevier, PubMed, Springer, and Wiley databases with “oral cancer”, “photodynamic therapy”, and “treatment modalities” keywords. Research shows that PDT can be an effective way to treat oral cancer due to its few side effects and minimal invasion. However, accurate evaluation of the efficacy of PDT requires further studies.