Objective This paper reports the results of standardized clinical caries examinations of 11-year-old children from across England and Wales, Scotland, Isle of Man, and Jersey in 2004/5. These co-ordinated surveys are the latest in a series which seek to monitor the dental health of children and to assess the delivery of dental services. Method The criteria and conventions of the British Association for the Study of Community Dentistry were used. Representative samples were drawn from participating strategic health authorities (SHAs), primary care trusts (PCTs), health boards (HBs), and local health boards (LHBs). Caries was diagnosed at the caries into dentine threshold using a visual method without radiography or fibre-optic transillumination. Results The results again demonstrated a wide variation in disease prevalence and care strategies across Great Britain. Mean values for D3MFT within the current English strategic health authorities ranged from 0.19 in Harlow to 1.32 in North Manchester and in Salford; in Wales mean values ranged from 0.69 in Vale of Glamorgan to 2.09 in Blaenau Gwent; while in Scotland they ranged from 0.59 in Orkney to 1.77 in Western Isles. Mean D3MFT across England was 0.64 (D3T = 0.32, MT = 0.06, FT = 0.25), across Wales it was 1.09 (D3T = 0.48, MT = 0.11, FT = 0.50), and across Scotland values were 1.29 (D3T = 0.52, MT = 0.17, FT = 0.60). Overall, 31.3% of children in England & Wales and 47.1 % of children inspected in Scotland had evidence of caries experience in dentine (D3MFT > 0, including visual dentine caries). As in previous surveys, the distribution of caries was highly skewed. Thus the mean caries experience for those with dentinal decay in England and Wales was 2.12, as opposed to the overall mean of 0.66; in Scotland the corresponding values were 2.74 and 1.29. Trends over time demonstrate an improvement in overall mean D3MFT for England and Wales since the 2000/2001 of 12-year-olds, although part of this difference is accountable to the younger age, at examination, in this survey. The mean value for those with dentine decay experience was also marginally less at 2.12 compared with 2.35 in the previous survey. (Figures for Scotland were not included in the 2000/2001 survey.) The care index was also found to be marginally lower than previously at 41% compared with 48% but again the younger age of the children would influence this value. Conclusion Dental health of 11-year-old children has been surveyed in Great Britain, Jersey, and the Isle of Man: being a slightly younger mean age than in previous BASCD surveys. Geographic variation in oral health is marked at both the local and national levels. Overall, the provision of operative care for those with dentinal decay is around 42%. While many children enjoy good oral health, sizable groups remain within the population of 11-year-old children who have a clinically significant burden of preventable dental disease. Key words: caries prevalence, dental caries, dental epidemiology, national surveys, oral health