Statistical processing of data was necessary to arrive at a reasonable conclusion regarding the chemical behavior of groundwater in a river basin. Multivariate analysis was done to elucidate the groundwater chemistry of a Central Kerala River basin. Hydrochemical parameters like EC, pH, TDS, TH, Ca, Mg, Na, K, Cl, F, HCO 3 +CO 3 , SO 4 , total Fe were estimated in the pre- monsoon and post-monsoon seasons. Factor and cluster analysis differentiated two distinct contributing components to the groundwater in the basin indicating that there is considerable mixing of the groundwater and surface water in the post-monsoon season whereas such a process is not significant during the pre-monsoon period. Different geochemical controls of the investigated parameters were also assessed.