The aim of our study was to determine fluorides (F-) content in the well water consumed as drinking water by some Moroccan populations in rural areas. All samples were collected between April and October 2011. Measurements were performed by an ion selective electrode. Thirty wells spread to cover most of the country and locally chosen based on the number of inhabitants who consume its water. All wells were in rural areas. The mean (+/- SD) of F- was 1.84 +/- 1.6 mg/L with a range from 0.42 to 8.95 mg/L Concentrations of F- in phosphate regions were higher than those found in other regions. More than half of the samples exceeded the current standard. Our study showed that water of some Moroccan regions is naturally rich in F-exposing people who consume it at high risk of fluorosis.