Water scarcity is a serious challenge in the Gaza Strip, a region that is mostly considered to be semi-arid. In this region, the population's options for provision of potable water are limited to desalination of saline groundwater. Six large brackish water desalination plants (BWDPs) and one seawater desalination plant are operating and providing drinking water along with small private plants. The BWDPs were assessed in terms of operational conditions and quality of their feed and permeate with the aim of estimating essential improvements required as well as performance significance. All these plants are reverse osmosis plants and their operational conditions are similar in terms of production, recovery rate, and energy consumption. The quality of the plants’ feed was found not to comply with WHO and Palestinian Standards in most cases, unlike the permeate from all plants. The assessment made through this study assists in better understanding of the current situation of the large-scale desalination plants in Gaza and recommending essential improvements needed to increase water production of these plants without increasing abstraction and feed quantities. In addition, multi-criteria analysis used to evaluate BWDPs performance may assist in prioritizing improvements application.