AIM: This paper aims to provide a review of the therapeutic effect of probiotics in the treatment of endodontic disease in humans. The administration of probiotic strains might play a role in caries lesion prevention and in the control of caries–related risk factors as well as therapeutic effect in endodontic disease.   BACKGROUND: Probiotics are live bacteria that confer a health benefit to the host. The organisms which have been used in the past as probiotics have been certain strains of Lactobacillus and Bifidobacteria. Probiotics have been shown to promote health in the intestines and the oral cavity through the consumption of certain yogurts and lozenges. Some of the mechanisms of action of these probiotics include the productions of bacteriocin–like inhibitory substances and the altering of the local pH, competing for nutrients, forming physical barriers and stimulating the immune response. The World Health Organization recognizes probiotics as a significant avenue of health preservation in the event that current antibiotics become useless due to the development of bacterial resistance. As far as is known, there are limited studies on probiotics in terms of their therapeutic effect in the treatment of endodontic disease.