Stable Cu-doped iron (III) oxide thin film electrodes that exhibit p-type behavior were synthesized by a spray pyrolytic deposition (SPD) method on conducting tin oxide-coated glass substrates for photoelectrochemical water splitting. The highest photocurrent density of 0.94 mA/cm(2) was observed under an illumination intensity of 40 mW/cm(2) for Cu-doped samples prepared using an optimal 0.01155 M Cu2+ at an optimal substrate temperature of 395 ° C with a total spray time of 100 s at 0.0 V vs. SCE. These Cu-doped p-Fe2O3 thin films were found to generate an optimum photoconversion efficiency of 1.3%. X-ray diffraction (XRD) data revealed that these films have mixed structures (α-Fe2O3 and CuFe2O4). The Cu dopant level in p-Fe2O3 was found to be 0.20% from X-ray photoelectron spectroscopic (XPS) data. © 2004 Published by Elsevier Ltd on behalf of the International Association for Hydrogen Energy.