A method for correcting skew images. The method first groups a scanned image into blocks with N*N pixels, and detects all the blocks to find out the edge areas with the larger luminance or chrominance difference afterward. Next, gradient angles of the edge areas are calculated, and a predominant angle is determined from among the calculated gradient angles; and (c) rotating the image according to the predominant gradient angle. The predominant gradient angle is taken as the skew angle for the image to be rotated. In consequence, a higher accuracy of image correction is achieved.