It is important that baseline studies of dental caries prevalence are available prior to the introduction of community water fluoridation. This survey was carried out during the winter of 1975/76 in the low-fluoride Barnsley Area (F= 0.1 parts/10(6)). Caries prevalence is in accord with that of other low-fluoride areas. The mean dmf was 4.5. For the group of children with rampant dental caries, the mean dmf value was much greater (11.3).