A systematic review was conducted to assess the relationship between frailty or one of its components and poor oral health. A search strategy was developed to identify articles related to the research question in the PubMed, EMBASE, Cochrane, LILACS, and SciELO databases that were published in English, Spanish, or Brazilian Portuguese from 1991 to July 2013. Thirty-five studies were identified, and 12 met the inclusion criteria, seven of which were cross-sectional and five were cohort studies. Of the 12 articles, five (41.7%) were rated good and seven (58.3%) as fair quality. The published studies applied different oral health and frailty criteria measures. Variations in definitions of outcome measures and study designs limited the ability to draw strong conclusions about the relationship between frailty or prefrailty and poor oral health. None of the studies that were evaluated longitudinally showed whether poor oral health increases the likelihood of developing signs of frailty, although the studies suggest that there may be an association between frailty and oral health. More longitudinal studies are needed to better understand the relationship between frailty and oral health.