This study investigates the impact of the Guriyeh earthquake swarm, which occurred between November 2017 and July 2018 in the Shushtar and Mianab aquifer systems, on groundwater levels and hydrochemistry. Groundwater data from production wells , geological maps, and earthquake bulletins were integrated to evaluate groundwater table fluctuations and variations in EC, TDS, pH, and major ions (Na⁺, K⁺, Ca²⁺, Mg²⁺, HCO₃⁻, Cl⁻, and SO₄²⁻) before and after the seismic swarm. Spatial interpolation using the Kriging method in GIS revealed that seismic activity altered groundwater flow paths through fracture opening and enhanced fault permeability, resulting in significant hydrochemical changes. Following the earthquake swarm, EC and TDS increased markedly along active faults and in areas with the highest seismic density, indicating the upward migration of deeper saline fluids. Spatial distributions of Na⁺, Ca²⁺, Mg²⁺, SO₄²⁻, and Cl⁻ shifted from widespread patterns to localized clusters, suggesting reactivation of fault-controlled hydrogeological pathways. Concurrent decreases in SO₄²⁻ and increases in pH likely reflect pore-pressure changes, intensified water-rock interaction, and mixing of shallow and deep groundwater. These findings demonstrate that the Gurieh earthquake swarm exerted a measurable influence on aquifer hydrochemistry and may serve as an indicator of concealed faults and preferential subsurface flow pathways.