We study the implementation of a meat-quality grading system, using the concept of the "marbling score", as well as image processing, neural network techniques and multiple regression analysis. The marbling score is a measure of the distribution density of fat in the rib-eye region. We identify five features used for grading meat images. For the evaluation of the five features, we propose a method of image binarization using a three-layer neural network developed on the basis of inputs given by a professional grader and a system of meat-quality grading based on the evaluation of two of five features with multiple regression analysis. Experimental results show that the system is effective. (C) 1999 Pattern Recognition Society. Published by Elsevier Science Ltd. All rights reserved.