Israel and the Gaza Strip shares the southern Mediterranean coastal aquifer with Israel. Long-term overexploitation in the Gaza Strip has resulted in a decreasing water table, accompanied by the degradation of its water quality. Due to high levels of salinity, most of the ground water is not suitable for both domestic and agricultural consumptions. The aim of this paper is to evaluate the chemical and microbiological qualities of the drinking water in Gaza Strip. The rapid rate of population growth in the Gaza Strip and dependence upon ground water as a single water source presents a serious challenge to future development. Data were collected from the Palestinian Ministry of Health on the concentration of total dissolved solids (TDS), chloride (Cl-) and nitrate (NO3-) in drinking water wells, and contamination of total and faecal coliforms in water wells and distribution networks. From the collected data on chemical water analysis, we obtained that the average concentration of TDS (1687 mg/l), Cl- (577 mg/l) and NO3- (131 mg/l) were higher than that of the World Health Organization (WHO) standard, i.e., 1000, 250 and 50 mg/l, respectively. Upon microbiological water analyses, total and faecal coliform contamination percentages were found to exceed that of the WHO standard, i.e., <5% for total coliform and free (0%) for faecal coliform for all water wells and networks distribution system, and the level of contamination in water networks were higher than that in wells. The chemical and microbiological qualities of drinking water thus deteriorated in Gaza Strip, and water demand is increasing rapidly due to rapid population growth and absence of alternative water resources. This may result in adverse human health impacts.