This was considered a pilot cross-sectional study to investigate a potential activity between protection against dental caries and water hardness with and without fluoride. Preliminary results are as follows: N Water Hardness* Fluoride(ppm) DMFS Group 1 519 Less than 50 Less than 0.2 5.2 Group 2 316 Approx. 250 Less than 0.2 5.1 Group 3 182 Less than 50 0.8 2.7 Group 4 146 Greater than 250 1.0 2.8 These results indicate that 1) the fluoride effect was obvious and obscured any effect from hardness; and, 2) if there was a "hardness" effect it was probably small and not detected with the population sizes. A future study will concentrate on high and low hardness only. * as Calcium carbonate mgms/liter