A simple, rapid and cost-effective technique, spray dry co-pressing process, was developed to prepare dense electrolyte thin films on porous anode substrates. Gadolinium doped ceria (GDC) electrolyte thin film with the thickness of 4 mu m was prepared successfully on porous NiO-GDC anode substrate by the spray dry co-pressing process. The GDC electrolyte thin film was dense and uniform, and was well bonded to the porous NiO-GDC anode substrate. An anode-supported solid oxide fuel cell (SOFC) with 4 mu m GDC electrolyte thin film was fabricated and its performance was evaluated at 400-600 degrees C with humidified hydrogen (3 vol.% H(2)O) as the fuel. The single cell showed an open circuit voltage (OCV) of 0.91 V and maximum power density of 771 mW cm(-2) at 600 degrees C. The results demonstrate that the dense GDC thin films prepared by the spray dry co-pressing process are suitable for low-temperature anode-supported SOFC applications. (c) 2009 Elsevier B.V. All rights reserved.