Background: Radon gas concentration in water has received increasing attention due to its adverse effects on human health. Several factors affect the behavior and nature of this gas in aquatic systems. This study aimed to investigate factors governing the spatial variations of 222Rn in the groundwater of the Jiroft plain, Iran. Materials and Methods: Water samples were collected from abstraction wells to analyze 222Rn and the physicochemical properties of groundwater. 222Rn activity was measured using a RAD 7 instrument. Results: 222Rn concentration of the groundwater ranged from 5.83 to 34.55 Bq/l. The 222Rn activity was larger than the permissible limit of the United States Environmental Protection Agency in many cases. Conclusion: Hydrogeological factors, such as depth to water, bedrock situation, aquifer transmissivity, and fault activity, had a good relationship with the spatial variation of 222Rn. No significant relationship was observed between 222Rn concentration and physicochemical parameters of groundwater.