The multi-stage flash distillation process was invented by Prof. R.S. Silver in 1957. The first plants were built in 1960. The development of the process triggered substantial growth in installed capacity throughout the sixties. The oil crisis of the early seventies fuelled this growth which tapered off in the mid-eighties. Over this period plant size increased although not as dramatically as had been predicted. Apart from the development of the on-line ball cleaning system and the high temperature additive, the development of the process has been evolutionary rather than revolutionary. Plant reliability and resistance to corrosion have been increased significantly. Further developments are likely to be made on the basis of applying past experience to new designs. There is the opportunity to reduce the cost of the plants by examining successful designs and developing a code of best practice.