A simple hydrothermal route was used to synthesize a nanowire network of Zn(OH)F at 120 °C, which was transformed into porous nanowire ZnO with the same morphologies by calcination in air. These as-prepared products were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy measurements. Luminescent and photocatalytic properties of Zn(OH)F and ZnO were also studied. Zn(OH)F exhibited a strong and broad emission band centered at 417 nm. Porous ZnO nanowire networks were found to decompose organic dyes photocatalytically.