The hydrogeochemical characteristics of shallow groundwater in the coastal areas of Kodiakarai have been investigated using geochemical analysis and statistical techniques. The geochemical data (electric conductivity, pH, total dissolved solids, Ca, Mg, Na, K, NO₃, SO₄, Cl, and HCO₃) of the water sample indicates that this water not suitable for drinking. The spatial distribution pattern indicates the total dissolved solids and electric conductivity were highly concentrated on the northeastern side, and that of sodium and chloride on the southwestern and northeastern side. The statistical treatment of the data (cluster, factor analysis) indicates three types of groundwater in the study area and that seawater incursion is the dominant process that influences the quality of the groundwater in the coastal region.