Among the desalination technologies available, reverse osmosis is currently considered as the most economical process. However, while RO membranes have been continuously improved over the years, they have had one major shortcoming; the susceptibility to fouling. Indeed, it appears that RO technology is limited in hydraulic performance by the raw water quality. In the case of direct seawater intake, extensive treatment is required upstream the RO process. Thus, the objective of this study was to evaluate the ultrafiltration membrane process as a RO pretreatment. The trials were conducted at Fuerteventura, Canary Island. The preliminary results showed that the Aquasource(R) UF membrane does not seem sensitive to high salinity of the seawater. Indeed, the mechanical resistance, as well as the specific flux of the UF membrane, remained stable. The dead-end filtration mode coupled with operation at low pressure allowed for very low power consumption. approximately 0.1 kWh per m(3) of permeate. Concerning the RO membrane evaluations, the hollow fine fiber (HFF) membrane was more efficient in terms of salt rejection, but the thin film composite spiral wound (SW) membrane operated at lower pressure (i.e, lower energy consumption). To date, the study continues in order to develop an integrated membrane system (UF/RO) to treat surface seawater.