The study was conducted to evaluate the groundwater quality of Aligarh city, (India). Groundwater samples were collected from 40 wells and analyzed for 20 water quality parameters in post-monsoon seasons during the year 2013. High coefficient of variance indicates variability of physico-chemical parameters concentrations in ground water. The descriptive statistical analysis was done beside Pearson correlation. From correlation analysis it was observed that very strong correlations exist between total hardness and Mg++ (0.99), TDS and total hardness (0.88), TDS and Chloride (0.87). In 100% of the samples recorded alkalinity and magnesium concentration were found higher than maximum permissible limit prescribed by BIS. Concentration of hardness, cadmium, pH, iron, lead, and total dissolved solids were also found above the standard limits prescribed by BIS. This reveals deterioration of water quality. It is therefore, suggested to take up regular monitoring of groundwater in areas of Aligarh city.