Water quality is considered as a major issue in mega cities of developing countries. The city of Faisalabad has over 4 million population. Groundwater is the main source of drinking water in Faisalabad. The groundwater quality should be regularly monitored in order to cope with the drinking water quality issues. An attempt has been made to understand the groundwater quality by using water quality index (WQI) at Chokera area, Faisalabad, Pakistan. It is a technique of rating water quality, is an effective tool to assess spatial and temporal changes in groundwater quality. Sixty groundwater samples were collected and analyzed for physico-chemical parameters using standard method of analysis. From the data obtained, the water quality index was calculated by adopting the method developed by Tiwari and Mishra. Water quality index rating was carried out to quantify overall ground water quality status of the area. The WQI index of the same has been calculated and the values ranged from 73 to 272. The WQI values from present study indicate the very poor water quality in the area. The analysis reveals the fact that the groundwater of the Chokera area needs a degree of treatment before consumption and needs to be protected from further contamination.