The photoelectrochemical properties of nitrogen-incorporated ZnO (ZnO:N) films prepared by reactive radio frequency (rf) magnetron sputtering were measured and compared with those of pure ZnO films. We find that nitrogen incorporation narrows the bandgap of ZnO and shifts the optical absorption into the visible light regions. We further find that the ZnO: N films provide considerable photoresponse in the long-wavelength regions up to above 600 nm. As a result, the ZnO: N films exhibit higher photocurrents than pure ZnO films under visible light illumination. The obtained photocatalytic activity indicates that ZnO: N films are potential candidates for photoelectrochemical water splitting and N incorporation can be utilized to improve the conversion efficiency. (C) 2007 The Electrochemical Society.