The focus of this study is to investigate the suitability of Lake Miri, a lake with high natural radioactivity in the southwest of Sudan, as a water source for nearby villages. Soil, water, foodstuffs and vegetable samples were collected and analyzed. The results indicate that the mean natural radioactivity level in the study area is 450 nGy/h, which is ten times greater than other places in Sudan with normal background (40 nGy/h) natural radioactivity, and these findings demonstrate that the average annual exposure of the population is 38.4 mSv.