The present invention relates a method and an apparatus for enhancing ultrasound image quality through a post-processing. A method for enhancing an image quality of a two-dimensional (2D) ultrasound image, comprises the steps of: a) decomposing the 2D ultrasound image into a plurality of images having a multi-resolution by N levels, wherein N is a positive integer; b) determining characteristics of each pixel in the decomposed image; c) performing an enhancement process for the decomposed image based on the pixel characteristics; d) performing 1.sup.st-level composition for the decomposed image; and e) repeatedly performing steps b) to d) until a size of the composed image is identical to that of the 2D ultrasound image.