OBJECTIVE: Identifying, through a systematic literature review, evidence of a possible association between obesity and dental caries. METHODS: A search of articles published between 2005 and January 2012 was performed in the Medline/PubMed, LILACS and Web of Science databases. The quality of scientifi c evidence of the selected articles was assessed by the items proposed for observational studies in the Downs & Black instrument. RESULTS: Initially, 537 references were found; after checking the titles and abstracts by two independent researchers, twenty-eight articles were selected for complete reading. Ten of them that assessed the primary and/or permanent dentition observed a positive association between obesity and dental caries and one study found an inverse association. According to the Downs & Black classifi cation, thirteen articles with good scientifi c evidence were found. CONCLUSIONS: The present review did not fi nd suffi cient evidence regarding the association between obesity and dental caries, and it did not clarify the possible role of diet and other possible effect modifi ers on this association.