In this study, a systematic quantum chemical calculation has been performed to investigate the synergistic effect of N and F doping on the photocatalytic properties of NaTaO3. The doping approach is found to be successful in extending the absorption curve of NaTaO3 toward the visible region. The presence of F not only passivates N-induced unoccupied midgap states but also facilitates the introduction of N by reducing the formation energy significantly. The band edge positions for the (N, F)-codoped NaTaO3 with respect to water redox levels are such that it can be a potential photocatalyst for overall water splitting. (C) 2014 Elsevier By. All rights reserved.