High population growth and increased exploitation of groundwater resources causes the degradation of groundwater quality. In today's world GIS has a wide applications in all fields of study. In this study GIS has been applied to evaluate the groundwater quality in the Peshawar district of Pakistan. The study is divided into two parts. In the first part 105 samples were collected in the field and were analyzed in laboratory for different important parameters such as pH, Ec, TDS, Alkalinity (HCO3), total hardness, Ca hardness, Mg hardness, NO3 (Nitrate) concentration, Cl-1 concentration and turbidity . These parameters were spatially modeled and analyzed using Spatial statistical techniques. In the second part a GIS based DRASTIC model was applied to assess the Groundwater vulnerable zones to pollution using six input parameters to the model such as depth to groundwater, net recharge, aquifer media, soil media, topography and hydraulic conductivity. After modeling the area was divided to low, medium and high vulnerable zones.