Reflecting recent merger trends in the banking industry of Korea and Japan, this paper examines the degree of competition before and after the bank merger wave. Two major implications are derived from empirical analyses. First, high levels of banking market competitiveness are detected after mergers in both the Korean and Japanese metropolitan areas. Second, although the level of market competition remains low throughout Japanese local cities, it is competitive compared with the metropolitan area of Korea. This paper concludes that market concentration brought about by bank mergers does not always result in low competitiveness.