Due to the resistance of Candida sp. to the usual antifungal, the demand for active principles found in the plants has been the target of diverse studies around the world. There are few in vivo and human studies on the antifungal activity of medicinal plants in the mouth. Native and imported medicinal plants, used by the Brazilian population for traditional medicine use, are the subject of study in this chapter. Thirty-eight Brazilian plants were related to information on species, family, name, used part, and medical indication of popular use. All the species mentioned had their extracts tested in vitro against C. albicans, C. tropicalis, C. krusei, C. parapsilosis, among other species that occur more frequently in the mouth. In the articles consulted, there is a great variation in Candida species tested and in minimum inhibitory concentration. The in vitro studies serve as information for the continuity of studies on the best performing plants, validate the popular belief about the use, and provide subsidies for the development of new products that are effective in the control of oral and systemic candidiasis and that are cheap and accessible for the population.