The present invention provides a device and a method for reducing impulse noise. The device includes a signal intensity detector, an intensity difference calculator, and a filtering circuit. The signal intensity detector receives an image signal and determines a first pixel having an extreme intensity, and a second pixel having a second extreme intensity of a window of the image frame corresponding to the image signal. The intensity difference calculator determines the intensity difference between the first pixel and the second pixel. The filtering circuit receives the image signal and optionally filters the image signal for reducing the impulse noise according to the intensity difference between the first pixel and the second pixel.