The authors report the growth of beta-Ga2O3 nanowires using a vapor phase transport method as a photoelectrochemical photocathode for hydrogen generation by splitting water. Under light illumination, it is observed that variations of the photocurrent with bias voltage depend strongly on the morphology and crystal quality of beta-Ga2O3 nanowires in electrolyte. Three-electrode photoelectrochemical (PEC) efficiencies of Ga2O3 nanowires are 0.006%, 0.803%, and 1.684% at zero bias voltage (V-CE) for the samples grown at 850, 900 and 950 degrees C, respectively. An essential requirement of resistance to reactions such as electrochemical corrosion, photocorrosion and dissolution at the solid-liquid interface was demonstrated. The results suggest that the Ga2O3 nanowires can be applied for designing high performance PEC devices.