Objective: This paper brings together summarised findings and comment on surveys of young children undertaken in Scotland, Wales and England in 2007-08. These surveys are the latest in a series using common criteria for measurement but changes in the consent arrangements for Wales and England mean that these datasets are no longer directly comparable with Scottish data. Method: Representative samples were drawn within the geographies of primary care organisations in the three countries, and in England within Local Authorities also, according to BASCD criteria. Consent was sought in three different ways. Children aged five were examined in England and those in Primary 1 (rising 6) were examined in Wales and Scotland. Examinations were conducted in schools by trained and calibrated examiners and caries was diagnosed at the dentinal threshold using visual criteria. Results: The impact of seeking positive consent appeared to depress the caries severity and prevalence in Wales and England whilst the reduced caries levels in Scotland may be attributed to the pro-active health improvement measures affecting this cohort. The results for positive consent suggest bias against participation of children with higher levels of tooth decay. Conclusion: Caries prevalence surveys of children at the start of formal education have been conducted in Great Britain. Those carried out with the need for positive parental consent have produced new baseline data. Data presented after 2007-08 should be annotated to show the participation rate and the inappropriateness of comparing data collected using different types of consent. Key words: epidemiology, dental caries, caries prevalence, national surveys, consent