This paper aims to turn complex groundwater data into comprehensible information by indexing
the different factors numerically comparative to the standards of World Health Organization
(WHO) to produce Water Quality Index (WQI). Water Quality Index (WQI) has been used to assess
groundwater quality and Geographic Information Systems (GIS) has been used to create maps
representing the spatial distribution of groundwater categories in Assiut governorate, Egypt. Water
Quality Index has been computed by Un-weighted Arithmetic Water Quality Index (WQIUA)
method and applied on 796 wells over eight years from 2006 to 2013. The results showed that
WQIUA values for drinking purposes were high and most of them reached higher or close to 100,
which indicated that the groundwater was polluted and unsafe for drinking. On the other hand,
the quality index of groundwater for irrigation purposes in most of the study area ranges between
55.78 and 78.38 (poor and very poor category); this means that groundwater is moderately polluted
and rather suitable for irrigation.