The natural radioactivity levels in groundwater, soil and crops have been determined in seven farms at Hail region in Saudi Arabia to assess any radiological hazards to the public, and to maintain a radiological map of natural radioactivity levels in this region. The radium isotopes (226 Ra and 228 Ra) were measured in groundwater samples collected from wells in these farms, and the 228 Ra activity concentrations exceeded the national guidance level of 2.7 pCi/L set by Saudi Arabian Standards Organization (SASO) and the WHO. These relatively higher activities did not contribute to the annual effective dose rate from the ingestion of both isotopes (226 Ra and 228 Ra) in the analyzed crops, which showed lower values than the upper limit of 1 mSv/yr. The activity concentrations of 228 Ra in soils of five farms were found to be higher than the world average value reported by the (United Nations Scientific Committee on the Effects of Atomic Radiation) UNSCEAR. These relatively higher activities contributed to the absorbed dose rate in air from external gamma radiation which was higher than the world average value of 57 nGy/hr in some farms. These high activities contributed also to the annual effective dose which showed values higher than the world average value of 0.07 mSv/yr for outdoor terrestrial gamma radiation in three farms. On the basis of these results, it can be concluded that the presence of such activities in the groundwater and crops samples do not pose any radiological hazards or significant risk to the public and animals, since they drink these waters. it may be recommended that the activity levels of the combined radium isotopes in the animal products (milk and meat) and the annual effective dose should be estimated to evaluate the contribution of the 228 Ra exceeded limits in these wells.