Background: Measurement of back ground concentration of uranium in drinking water is very important for many reasons, specially, for human health. The uranium concentration in drinking water in many counties is a matter of concern for clinical and radioactive poisoning.

Materials and Methods: The uranium concentration in drinking water is determined using laser flourimatric uranium analyzer. For this purpose after sampling, sample handling and sample preserving, sample preparation and treatment for reduction of organic matter, the concentration of uranium is measured.

Results: To determine the uranium concentrations in drinking water in Iran , nearly 200 water samples were collected from all sources supplying drinking water in 21 provincial centres in the country. The wells were found to be the main source for drinking water. Uranium in the samples was measured by a laser fluorimetry technique. According to results, the concentration values found in the wells ranged from 1.0 to 10.90 μgL^-1, while nearly 95 percent of the cities had uranium concentrations in the wells at less than 4.70 μgL^-1. Surface waters showed uranium concentrations in the range of 0.75 to 2.58 μgL^-1. The daily intake of uranium from drinking water was estimated to range from 2.04 to 21.80 μgd^-1, with the mean value of 5.44 μgd^-1.