Using a recently developed micro-procedure, small samples of enamel, dissolved from the labial or buccal surfaces of permanent anterior teeth, were analysed to establish the pattern of fluoride distribution in the enamel surface. Considerable differences in fluoride-concentration were found from place to place in the tooth surface but certain consistent patterns of fluoride distribution emerged. These patterns, which varied with the age of the tooth, appeared partly attributable to tooth wear and partly to both pre- and post-eruptive uptake.