A pilot plant membrane bioreactor has been tested in parallel with a full-scale activated sludge wastewater treatment plant fed on the wastewater from a textile factory. The possibility to upgrade the final effluent for internal reuse was investigated. The pilot and full-scale plants are located in a textile factory (Boselli & C., Olgiate Comasco, North Italy) which manufactures and finishes polyester fabric. The activated sludge wastewater treatment plant (WWTP) is an extended aeration system. The MBR pilot plant is a ZW-10 bench hollow fibre module (membrane surface area: 0.93 m2) submerged in a 200 L tank. Performance and operation of the membrane bioreactor (MBR) were evaluated in terms of permeate characteristics and variability (COD, colour, total N and P, microbiological counts), of membrane specific flux (l m(-2) h(-1) bar(-1)) and other operational parameters (sludge growth and yield).