Evidence concerning the influence of fluoride drinking water on gingivitis is inconsistent. In order to determine whether fluoride in drinking water up to the level of 2 ppm has any effect on the prevalence, extent or pattern of gingivitis in anterior labial units, the gingival health of 386 15-year-old children, continuously resident in West Hartlepool, a high fluoride area (1.5–2.00 ppm F), was compared with that of 38115-year-old children from York, a low fluoride area (0.2 ppm F). The method of measurement was that described by Jackson (1965). It was concluded that fluoride in drinking water, at least up to the level of 2 ppm, has no influence of clinical significance on the prevalence of gingivitis, on the extent, or on the pattern of gingivitis in individual papillae and margins associated with incisor and canine teeth in 15-year-old-children. In both communities prevalence of gingivitis was higher in boys than in girls. However, when only those children with a good standard of oral cleanliness were considered this sex difference disappeared, suggesting that the observed sex difference could be due to differences in the standards of oral cleanliness between boys and girls. A distinctive pattern of gingivitis in papillae and margins associated with anterior teeth was observed in all four groups studied, and this pattern was essentially the same as that observed independently by Jackson (1965) and Sutcliffe (1968), suggesting that this pattern is universally true.