Groundwater resources make up an important portion of potable and irrigation water in Iran, making it important to monitor toxic elements of pollutants in these resources in order to protect the inhabitants' health. The current study has been carried out to assess the health risks, caused by trivalent inorganic arsenic-polluted groundwater in Qaleeh Shahin Plain, an important agricultural region in Kermanshah Province. For this purpose, in total 20 groundwater wells have been chosen randomly. The samples have been filtered (0.45 μm) and preserved with HNO3 to a pH level lower than 2, then to be taken in acid-washed polyethylene bottles and kept at a temperature of 4 °C for further analysis. Finally, As(III) concentration has been determined, using ICP-OES with three replications. Results have shown that mean content of As (ppb) in groundwater samples were 6.0 ± 3.0 for winter and 9.0 ± 6.0 for summer in 2014. Also, according to the results, the computed values of the hazard quotient (HQ) and target risk (TR) of groundwater samples were below 1 and less than 10E-06, respectively; therefore, non-carcinogenic effect (chronic risk) and carcinogenic exposure are not likely for the inhabitants of this study area. However, due to over and long-term use of agricultural inputs in the study area, it is recommended to have some paramount consideration for better management and care of using agricultural inputs, especially chemical fertilizers, arsenical pesticides, or herbicides, and for treatment of As-polluted groundwater with proper removal methods prior to preparation of drinking water.