Ashkelon - the world's largest reverse osmosis desalination plant - is providing successfully its full capacity of drinking water (330,000 m(3)/d) at the lowest production cost for this type of project. The project has been developed as a BOT (Build, Operate and Transfer) by a consortium made of three international companies: Veolia water, IDE Technologies Ltd. and Elran Infrastructures Ltd. This paper will highlight the main points of this project.