Introduction: The use of medicinal plant compounds for cancer treatment has been considered since ancient times. This systematic study aimed to conduct a review on the effects of medicinal plant extracts on oral cancer cell lines in vitro. Methods: In this systematic study, articles were searched in databases, including PubMed, Google Scholar, ScienceDirect, Web of Science, and Scopus, using keywords as "herbal drugs", "medicinal plants", "extract", "essence", "oral cancer", "in vitro", and "clinical trials". Results: After searching the articles according to inclusion and exclusion criteria, removing duplicates, and reviewing full-text articles, the researchers entered the data of all the collected articles into Endnote X9. Initially, 14,650 studies were identified, but after applying the inclusion/ exclusion criteria, 21 studies were selected. Conclusion: According to the inclusion and exclusion criteria, 21 studies have been selected. The study's findings have revealed that medicinal plants have the potential to inhibit the growth of oral cancer cells, making them a promising candidate for further research on cancer treatment.