Currently over 12,500 industrial desalination plants, with an average production rate of 22.8 million m(3)/d, are operating worldwide to alleviate water shortage problem. In this contest, pressure driven membrane operations are today largely utilized. They compete successfully with the more traditional thermal systems due to their lower energy consumption. However, critical issues still remain open: improvement of water quality and plant global recovery factor, reduction of desalted water cost and brine disposal problem. Recent developments make realistic to affirm that integrated membrane systems might offer one of the most reliable solution to solve these problems and also a sustainable development of desalination processes. Integrated membrane processes represent an attractive opportunity because of the synergic effects that can be reached, the simplicity of these units, the possibility of advanced levels of automation and remote control. In this logic well fit in also temperature driven membrane operations, such as membrane distillation and membrane crystallization: they allow increasing fresh water recovery factor, recovery of the crystals naturally present in the concentrated streams of the desalination plants, reduction of brine disposal cost and its negative environmental impact. In this work seven flow sheets for seawater desalination have been proposed, analysed and compared. In each of them different membrane units have been integrated in pre-treatment and post-treatment stages for reaching the process intensification goals, overcoming the limits of the single units and, thus, improving the performance of the overall desalination process.