OBJECTIVE To review the current literature regarding the anti-caries efficacy of fluoride varnishes. To analyse a series of studies designed to detect the caries preventive efficacy of fluoride varnishes by means of meta-analysis. METHODS Current literature on fluoride varnishes has been reviewed. An evaluation of the results of the available in vitro, animal and human studies on the anti-caries efficacy of these preventive agents was performed. A systematic literature search and a meta-analysis were also performed to assess the caries preventive effects of fluoride varnishes. The purpose of this analysis was to calculate the overall preventive efficacy of clinical fluoride varnishes treatment studies, based on defined methodological criteria. RESULTS The efficacy of fluoride varnishes in caries prevention is clearly demonstrated in several experimental studies. Clinical trials show caries incidence reduction ranging approximately from 18% to 70%. Nevertheless, available studies show a high degree of heterogeneity and only three were found to meet a series of defined methodological criteria. All the three studies were based on a comparison between 0.2% NaF rinses and a fluoride varnish. The meta-analysis showed no significant differences between the two treatments. CONCLUSIONS Available data suggest that fluoride varnishes are a useful tool in caries prevention. One may conclude that fluoride varnishes, when applied regularly, demonstrate good caries preventive properties.