The objective of this study is to investigate the groundwater influences on sandstone in Horus temple, in addition to studying the deterioration processes affecting the temple building materials. Specific investigations were carried out to measure the groundwater features and quality both inside and outside the temple to evaluate the resulted deterioration processes. Our results argue that the temple was built on a hill of silt and clay belonging to the Cretaceous Era; it rises on the south part of the Nile valley far from the Nile for about 1200 m. Groundwater quality is strongly influenced by the dominating minerals and stone aquifer affected by three major water sources. The temple faces many deterioration processes due to the effect of groundwater characterized by high salinity index. These processes led finally to two main mechanisms, (the first related to micro-deterioration and the second resulting from structural defects). These mechanisms affirmed that the stone building materials were highly characterized by weakness, fracture, disintegration, cracks and crevices collapsing of their components. Furthermore, the dominating major salt species are halite, gypsum, sylvite and thenardite and minor quantities of carbonates and bi-carbonates, in addition to phosphate as or trace constituents.