In the Western Desert of El-Minia Governorate, the area of future strategic inventory to Egypt, groundwater is the chief source of water supply for agriculture and domestic uses. Field trails were conducted for two successive growth seasons of tomato grown in newly reclaimed lands, irrigated with groundwater (EC 2.24 and 3.86 dS m^-1), subjected to water stress (irrigation every 3, 4, and 5 days), and fertilized with different potassium levels. The experiments were carried out at the Agricultural Experiments and Research Center, Faculty of Agriculture, Minia University, El-Minia Governorate, Egypt, to evaluate groundwater suitability for irrigation and to determine effects of groundwater salinity and irrigation intervals on soil salinity build up and some soil chemical properties using drip irrigation system under application of potassium fertilization. The obtained results indicated that groundwater is suitable for crop irrigation in terms of some chemical criteria features of water quality such as sodium adsorption ratio, pH, Na/Cl ratio, Ca/Mg ratio, and magnesium hazard.  On the other hand, groundwater is unsuitable for crop irrigation due to other features such as high concentration of total dissolved salts (ranged from 1477 to 2497 mg L^-1) and water EC (ranged from 2.24 to 3.86 dS m^-1), chloride and bicarbonate concentration. The higher electrical conductivity values lie under degree of restriction on use ''Severe'', indicating that using such groundwater in irrigation may cause a severe salinity problem in soils on the long-term saline irrigation if not managed properly.  Higher levels of water salinity and lower irrigation intervals significantly increased initial soil electrical conductivity, soil salinity build up, and soil pH due to increased water salinity levels and inadequate irrigation and drainage water.  As a result of physicochemical groundwater characteristics, groundwater in the Western Desert aquifer is may be used carefully for irrigation of some suitable crops under certain conditions.  Results of this research evidently specified that if suitable irrigation management practices were adopted, it is feasible to irrigate crops using relatively high saline water under arid conditions.