In view of the implementation of ultrafiltration for large-scale drinking water applications, the properties of the membranes, the types of modules and the mode of operation had to be reviewed. In this respect the surface porosity and adsorption characteristics of the membranes were improved, module sizes were adapted, and the semi-dead operational mode was pioneered. Thus treatment costs could be lowered to about DM 0.2-0.4/m(3) of treated permeate. This makes ultrafiltration a very promising unit operation for the next century. In this paper the most recent large-scale applications of the players in this field will be discussed.