ABSTRACT: The water quality and quantity of coastal aquifers are increasingly adversly affected due to changing climate conditions and increasing anthropogenic activities. This study was conducted to determine the water quality and pollutants of the Erdemli Coastal Aquifer (ECA). In this study, groundwater sampling was carried out in August 2020 to determine the physical and chemical properties of the water. The obtained results were evaluated according to the World Health Organization (WHO) drinking water standards. It was found that the electrical conductivity values were quite high in samples taken from certain points near the Mediterranean coast of ECA. These samples also exhibited high sodium (Na+) and chloride (Cl−) concentrations, exceeding the recommended WHO limits. Another significant problem in the ECA is nitrate (NO3−) pollution. The nitrate concentrations in the August 2020 samples ranged from 2.17 to 131.51 mg/L, with 15 samples exceeding the limit value (50 mg/L). Some samples also exceeded the WHO-established limit values for trace element concentrations (Al, Fe and Ni). When assessing the groundwater in the study area for agricultural irrigation water quality, it was determined that waters in areas with active seawater intrusion were not suitable for irrigation purposes. The study area and its vicinity have been witnessing the opening of new agricultural areas on a daily basis. This situation further exacerbates the pressure on the declining water resources in the ECA. As a result, the implementation of sustainable integrated water management in ECA is urgently needed.