This report presents the possibilities of utilising membrane methods for the treatment of industrial wastewater, covering following different systems: substance separation with porous membranes; substance separation with non-porous membranes, and membrane activation methods. The last is an aerobic biological wastewater treatment method where the unit for secondary treatment is replaced by a membrane filtration unit. This latter method is the focus of the article. The positive effects of these methods are described, such as high influent concentrations, small plant volumes, high demands on effluent quality, re-use of purified wastewater, evenly distributed hydraulic load, and low area availability. The report presents examples of how these methods have been successfully used in both pilot plants and on an industrial scale. It can be concluded that membrane methods can successfully be utilised in industrial wastewater treatment, with new applications being found on an almost daily basis.