Thane is the third most industrialized district in the Maharashtra state. The area is characterized by hard water and high salinity hazard due to it’s proximity and hydraulic connection with the sea. Therefore an Attempt has been made to assess the physico-chemical Parameters of ground waters of Thane Region, Maharashtra during Oct. Nov. 2008. Statistical studies have been carried out by calculating correlation coefficient between different pairs of parameters and t-test applied for checking significance. The observed values of physico-chemical parameters of ground water samples were compared with standard values recommended by WHO. It is found that an appreciable significant positive correlation holds for electrical conductivity with Na, Cl- and T.D.S. total hardness with Ca and Mg, pH with C.O.D. T.D.S. with Na, Cl-. Negative correlation was found between electrical conductivity and nitrate, with SO42- and nitrate,Total hardness with C.O.D. All the physico-chemical parameters of ground water of Thane region are within the highest desirable limit or maximum permissible limit set by WHO, except chemical oxygen demand, total hardness and alkalinity values for most the ground water samples