Introduction: Over twenty developed and developing countries have regions with endemic floursis, on the other hand tooth decay as an infectious disease in human societies is reported to occur due to the shortage of fluoride in water. Since decayed, missing, and filled teeth DMFT is considered a 52 -character indicator in health equity, the present research aims at studying the relationship between the concentration of fluoride and other variables such as location, parents’ employments, visiting dentist, tooth brushing, and using mouth washes with DMFT index in Haji Abad, Hormozgan.

Materials and methods: This is a descriptive-analytical study. Where the population included 12-14 year old students from Haji Abad, Iran. The sample size of 336 subjects obtained using the calculation method of descriptive samples in the finite population situation and considering the coefficient interval of 95%.They were measured using SPADNS method The samples were conducted in triplicates and the average values were considered.Then the measured samples were coded using SPSS16 software and finally the coefficient correlation test as well as regression analysis was carried out.

Results: DMFT index was the average of 1.4±0.53 and the concentration of fluoride was the average of 0.82±0.29 In the present study, the coefficient value between fluoride concentration and DMFT was equal to 0.929 (Pierson correlation coefficient P<0.001).The study showed that the variables such as location, parents’ employments, visiting dentist, tooth brushing, and using mouth washes has a significant relation with DMFT index.