The north east of Tunisia ore deposits (Hammam Zriba) contain a large amount of fluorides constituting a risk of environmental pollution as well as risks to human and animal health. The aim of our work was to assess the levels of fluorides in the water from the east of Tunisia region. This analysis study included 78 water samples taken during 3 days in the year 2019, at Hammam Zriba delegation. The determination of fluorine concentration in the samples was carried out by potentiometer with a selective electrode type ISE combined Fluoride perfectIONTM. High Fluoride concentrations were found at a mean of 1.62 ± 1.18, 1.45 ± 0.98 and 2.65 ± 1.61 mg/lit, respectively, in running, deep and stagnant waters.