A functional keratin/indium tin oxide (ITO) composite was prepared by a route involving an ionic liquid dissolving process and a wet-chemical codeposition technique. The crystal structure and morphology of ITO were investigated by X-ray diffraction and transmission electron microscopy, respectively. The factors influencing the crystal structure and the size of the ITO were investigated in detail. The optimal In/Sn ratio, reaction temperature, and pH value were found to be 10:1, 70°C, and 7, respectively. The sheet resistance of the composite reached 0.39 kΩ/□. In addition, the composite films possessed a perfect UV protection ability with a UV protection factor of up to 43.78. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39641.