We report the fabrication of cadmium sulfide (CdS) quantum dot-decorated barium stannate (BaSnO3) nanowires and their application as photoanode for photoelectrochemical water splitting. First, polycrystalline BaSnO3 nanowires, which have a perovskite structure, were prepared by electrospinning their polyvinylpyrrolidone polymer precursors and calcining the resultant polymer fibres. Then, CdS quantum dots were decorated onto the BaSnO3 nanowires with a wet-chemical method. Our results show that the hybrid photoanode made of the CdS quantum dot-decorated BaSnO3 nanowires exhibits a high photocurrent density up to 4.8 mA cm-2 at 0 V (vs. saturated calomel electrode), which corresponds to a hydrogen generation rate of 90??mol (h cm2)-1 in theory. Its favourable performance was attributed to the effective charge separation at the type II staggered gap heterojunction formed at the BaSnO3/CdS interface, and the low charge recombination in BaSnO3 nanowires during transport. Our findings indicate that the water