In this work, the concentrations of natural Uranium and the annual effective dose (E_T in Sv·y-¹) in drinking water for Nineveh Governorate in northern Iraq were determined using a pulsed-laser Kinetic Phosphorescence Analyzer (KPA). Furthermore, the relationship between pH for water samples and the concentration of Uranium was studied. The drinking water samples are taken approximately from all regions of Nineveh as; 15 samples of tap water are taken from refinery stations, 13 samples of water samples are taken from wells that are used for drinking, and 18 samples of drinking water are withdrawn from wells in Adayyah region (this region is located near nuclear wastes site). Thus, the total studied samples are 46. The results of Uranium concentration for all samples ranged from 2.61 ± 0.08 to 9.14 ± 0.012 μg·L^-1 with an overall average value about 5.87 ± 0.046 μg·L^-1, and the total annual effective dose ranged from 2.3 to 8.04 μSv·y^-1. The results also showed that the pH number increases with increasing Uranium concentration and have, in general, high values in well water.