The research evaluated the fluoride concentrations by collecting samples of drinking water twice a month through one full year. Then the fluoride concentrations was measured and compared with the recommended values set by international environmental and health organizations .The results indicate that there is fluctuation in the fluoride concentrations . It ranges from (0.075)mg/l to (0.225)mg/l with an average of (0.147)mg/l . All samples concentrations are lower than the guide values. Thus the water is suitable for drinking as far as this characteristic concerned , with an expectation that dental caries cases may be appearance .
The results also indicated that all fluoride concentrations in Mosul city drinking water were less than the optimum value which is (0.7)mg/l , according to EPA. This value was stabilized according to the mean value of maximum daily temperature for the Mosul city (28.42) ○C over the last (5) years. However, to avoid consumed excessive dosage of fluoride, the fluoridation should not be practiced unless it is advised by the specialists in the nutrition, public health and dentistry. The fluoride may be supplied to the human by sources other than water, also there is a variety in the amount of the fluoride consumed by different persons.

Key words : drinking water / fluoride concentration .