Over groundwater exploitation owing to population, urbanization and industrialization make the groundwater unfavorable for living beings. This study deals with the assessment of groundwater quality in Gudiyattam and Vaniyambadi blocks of Vellore district, Tamil Nadu, India where groundwater is the major source of drinking due to deficiency in surface water. The significant physicochemical parameters such as pH, conductivity, total dissolved solids, chlorides, total alkalinity, calcium hardness, magnesium hardness and sulphate were assessed. Correlation matrix, box plot, multivariate statistical tools such as cluster analysis and principal component analysis were applied to groundwater quality analysis. The groundwater samples were assessed for its applicability in irrigation and drinking purposes and geographic information system techniques are used for mapping consequence. The parameters analyzed were compared with Bureau of Indian Standards (BIS) and WHO standards. Box plot analysis revealed that total dissolved solids and electrical conductivity was strongly correlated. Correlation analysis exhibits strong correlation (R2>0.7) between total dissolved solids and electrical conductivity, anions such as Ca2+ and Mg2+ for both the study areas. © 2015 Academic Journals Inc.