Abstract:The application of pesticides indoors and on agricultural lands increased dramatically in recent years in the Jazan area (Saudi Arabia) to control termites and the vectors of diseases, such as Rift Valley Fever (RVF) and malaria. This practice increased the potential risk of pesticide contamination of surface water and groundwater. In this study, samples of 44 wells and 3 dams were collected; the samples were analysed for the presence of 15 pesticides used in the Jazan area. The results showed that the most detected compounds in the surface water samples were diazinon, Dichlorodiphenyltrichloroethane (DDT), fenitrothion and cyfluthrin, with average concentrations of 0.098, 0.104, 0.321 and 0.394 µg L −1 , respectively. In the groundwater samples, the most detected insecticides were diazinon, dieldrin and fenthion, with average concentrations of 0.117, 0.005 and 0.472 µg L −1 , respectively. In general, detected concentrations of organophosphorus insecticides slightly exceeded the allowed Maximum Residue Limit (MRL) of the European Union, which is 0.1 µg L −1 , in some samples. However, the findings of this study about the safety of water resources in the Jazan area were not alarming because the detected concentrations were below the MRL and lower than the limit of the sum of all individual compounds detected in the same sample. More extended investigations are highly recommended.