Probiotics have been found to be beneficial to host health. Their primary use in medicine has been for the management of intestinal tract problems. In recent years, probiotics have been used as a treatment to promote oral health. The aim of the present study was to review published studies regarding probiotics and their effects on the oral cavity. Studies reporting the anticariogenic effects of probiotics, their use in the treatment of periodontal disease, a reduced crevicular fluid volume and cytokine content, as well as their use in the treatment of halitosis and Candida albicans were identified. Studies assessing residence time of probiotics in the oral cavity were also selected for retrieval. Most authors concluded that the use of oral probiotics was associated with an improvement in oral health, including a significantly reduced level of cariogenic and periodontal pathogens and a lower crevicular fluid volume and cytokine concentration.