Hydrogen energy is considered as an ideal candidate energy of traditional fossil fuels. Oxygen evolution reaction (OER) is a crucial reaction for the sustainable hydrogen generation as a half reaction of water splitting. It is important to develop efficient electrocatalysts for the OER. Herein, the porous iridium nanowires (Ir PNWs) with polyallylamine hydrochloride (PAH) as a complex-forming agent and capping agent have been successfully synthesized through a one-pot hydrothermal approach. Benefiting from the inherent anisotropic characteristic of one-dimensional nanowires structure, abundant microporous channels and high atom utilization efficiency, the synthesized Ir PNWs possess very large electrochemically active surface area (118.2 m(2) g(-1)), and thus exhibit superior electrocatalytic activity and stability towards the OER compared with commercial RuO2 catalyst and other Ir nanocrystals.