Dilute dispersion/emulsion of ultrafine water droplets containing a variety of salts is usually present in fuel oil, jet fuel, diesel oil and crude oil. Removal of salt and water from the oil is difficult. It is proposed here that a hydrogel hollow fiber membrane of regenerated cellulose with wash water flowing on one side and oil flowing on the other side could desalt the fuel oil. Preliminary experiments employing Cuprophan((R)) regenerated cellulose hollow fibers demonstrate that salt was transferred to the wash water from a no. 2 fuel oil stream containing saline droplets 4 vol.%.