The recognition of naturally occurring radioactive material (NORM) associated with oil and gas fields started nearly at the same time as the discovery of radioactivity itself. Radium in produced water is typically the source of the majority of the NORM. Four processes within oil and gas formations, solubility, alpha recoil, cation exchange, and coprecipitation lead to high radium activity in pore fluids. These processes occur regardless of the type of reservoir (conventional high permeability oil and gas reservoirs or unconventional low permeability organic-rich shale source rocks). Following well stimulation via hydraulic fracturing fluids and some solids that return to the surface contain elevated radium. The data on radium from oil and gas wells across the USA is severely lacking relative to the volumes of produced water, especially considering that large volumes are beneficially used or disposed of to surface waters. Novel treatment and accurate measurements of radium are necessary prior to beneficially reuse or dispose produced water in order to protect human and environmental health. More measurements of radium in produced water should be obtained and made publicly available.