Porous titanium dioxide (TiO₂) nanowires were synthesized via a surfactant-free hydrothermal method followed by acid-washing process and calcination. The structures and morphologies of products were characterized by field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), and Brunauer-Emmett- Teller (BET) N₂ adsorption-desorption analyses. The analysis of FESEM suggested the precursor was composed of a vast of uniform nanostructures like wires. The nanowire-like precursor was transformed into the porous nanowire after acid-treatment and calcination at 500°C for 2 h in air. The surface area of as-synthesized TiO₂ nanowires calculated by BET is 86.4 m²/g. Furthermore, the photocatalytic properties of synthesized porous TiO₂ nanowires were evaluated through the degradation of methylene blue (MB) and Rhodamine B (RhB). The results clearly suggested that the as-prepared porous TiO₂ nanowires showed remarkable photocatalytic performance on the degradation of RhB and MB due to their small size of nanocrystallites and the porous naonstructure.