This paper evaluated the feasibility of using MD technology to desalinate brines from thermal desalination plants. A state-of-the-art MD bench scale unit was built and the performance of different MD membranes was compared under various operating conditions using synthetic saline solutions, brine from a thermal desalination plant and seawater from the Arabian Gulf. Overall, MD was shown to be a feasible and effective process capable of consistently producing high quality distillate (conductivity < 10 ¦ÌS/cm) from high salinity brines (70,000 mg/l TDS) from a thermal desalination plant. A consortium consisting of the ConocoPhillips Global Water Sustainability Center (GWSC), Qatar University (QU) and Qatar Electricity & Water Company (QEWC) was formed to operate pilot-scale MD systems to desalinate brines from a full-scale thermal desalination plant in Qatar to determine process economics and address specific field conditions of the region.