Studies concerning the removal of oil from model wastewater using the hybrid process combining ultrafiltration and nanofiltration were performed. The separation and transport characteristics of the employed membranes were determined. The content of oil in wastewater was estimated by the determination of total organic carbon and oil concentration measurements using a Horiba OCMA-310. The investigations of oil wastewater treatment were carried out in two stages. The permeate obtained from the UF process (the first stage) generally contains less than 6 mg/dm³ of oil, whereas in the NF process (the second stage) the complete removal of oil was achieved.