The objective of this study is to evaluate the reliability of DEA for the measurement of efficiency of Commercial banks in Korea using the DEA methods. DEA is basically a mathematical programing technique initially developed by Chanes, Cooper and Rhodes(197n) to evaluate the relative efficiency of not-for-profit organizations where multiple outputs are produced with multiple inputs. This study show that DEA approach is not only usefulness in evaluating performance of banks but also a useful bank management tool.