Data sources: The Cochrane Oral Health Group Trials Register CENTRAL, Medline, Embase, PsycINFO, CINAHL, Web of Science conference proceedings (IADR and ORCA), reference lists and Dissertations Abstracts were searched. Study selection: Randomised controlled trials assessing the effectiveness of 1:1 dietary interventions in a dental care setting were included. This could be brief advice, skills training, self help materials, counselling or lifestyle strategies delivered by any member of the dental team. Data extraction and synthesis: Two reviewers independently screened and abstracted data with disagreements resolved by discussion and a third review author. The Cochrane risk of bias assessment tool was used. Results: Five studies were included; two were at high risk of bias, three were at unclear risk of bias. Two were multi-intervention studies where the dietary intervention was one component of a wider programme of prevention, but where data on dietary behaviour change were reported. One of the single intervention studies concerned caries prevention. The others concerned general health outcomes. No studies were aimed at preventing tooth erosion. Four out of five studies found a significant change in dietary behaviour in at least one of the primary outcomes. Conclusions: There is some evidence that one-to-one dietary interventions in the dental setting can change behaviour, although the evidence is greater for interventions aiming to change fruit/vegetable and alcohol consumption than for those aiming to change dietary sugar consumption. There is a need for more studies, particularly in the dental practice setting, as well as greater methodological rigour in the design, statistical analysis and reporting of such studies.