Thin layers of indium tin oxide are widely used as transparent coatings and electrodes in solar energy cells1, flat-panel displays2, 3, antireflection coatings4, radiation protection5 and lithium-ion battery materials6, because they have the characteristics of low resistivity, strong absorption at ultraviolet wavelengths, high transmission in the visible7, high reflectivity in the far-infrared and strong attenuation in the microwave region. However, there is often a trade-off between electrical conductivity and transparency at visible wavelengths for indium tin oxide and other transparent conducting oxides. Here, we report the growth of layers of indium tin oxide nanowires that show optimum electronic and photonic properties and demonstrate their use as fully transparent top contacts in the visible to near-infrared region for light-emitting devices.