This publication presents the results of an IAEA Coordinated Research Project (CRP) on Optimization of the Coupling of Nuclear Reactors and Desalination Systems. The overall scope of the CRP was to encompass research and development projects focused on optimized coupling of nuclear and desalination systems in the following areas: nuclear reactor design intended for coupling with desalination systems; optimization of thermal coupling of nuclear steam supply systems and desalination systems; performance improvement of desalination systems for coupling; and advanced desalination technologies for nuclear desalination. A total of nine nuclear reactors were examined for optimal coupling with desalination systems within this CRP. They are all of the water cooled reactor type and are in various degrees of development. The commercial seawater desalination processes which are proven and reliable for large scale production of desalted water are multi-stage flash (MSF) and multi-effect distillation (MED) for distillation processes and reverse osmosis (RO) for membrane processes, as well as hybrid technologies such as MSF-RO and MED-RO. Different coupling options between the above nuclear and desalination technologies have been investigated within the CRP and were optimized with respect to safety, operational flexibility, reliability/availability and economics.