Triggered by the Asian financial crisis in 1997, corporate governance has become an important topic for many Korean companies. Particularly, Korea‟s large family-owned conglomerates, chaebols, went through significant changes in terms of corporate governance. There has been a widely held belief that the lack of proper corporate governance in Korean companies, notably chaebols, forces them to suffer from low performance. Changes in corporate governance, therefore, is expected to enhance company performance. This paper is an exploratory study to address this issue. Specifically, it has an indepth look at the case of Mando Corporation to show how corporate governance improved management performance in terms of increasing shareholder value. The roles of the board of directors, large shareholders, and professional managers are explained and contrasted in the context of rapidly evolving dynamics of changes in the corporate governance of the company.