Image sensors and methods of fabricating the same are provided. The image sensor includes a blocking pattern disposed on photodiodes. The blocking pattern is formed of insulation material having a metal diffusion coefficient which is lower than a silicon oxide diffusion coefficient. Therefore, dark defects of the image sensor are reduced. In addition, the image sensor includes a color-ratio control layer. The color ratio control layer controls color ratios between the sensitivities to blue, green and red. As a result, color distinction of the picture that is embodied by the image sensor can be improved.