Industrial-scale ultrafiltration (UF) membrane systems have gained wide acceptance for producing safe drinking water. Laboratory and pilot plant studies are often carried out prior to the design of full-scale water treatment plants. Emphases are laid on how accurately these laboratory and pilot plant studies represent actual industrial-scale systems and the limitations. A case study which encompasses laboratory experiments, pilot plant and industrial-scale UF systems has been carried out in Malaysia using the same type of modified polyethersulfone hollow fiber UF membrane and surface raw water source. This research elaborates on the practical utilization of laboratory experiments and pilot plant results on the design and scale-up for industrial-scale water treatment plants. The results obtained in filtrate quality, transmembrane pressure and specific electricity requirements elucidate that both laboratory- and pilot-scale studies are essential to determine the detailed design criteria of an industrial-scale UF membrane water treatment plant with limitations that require attention. Design engineers are able to reduce the safety factor allowance and minimize cost by utilizing laboratory- and pilot-scale results for the scale-up of UF membrane water treatment plants.