Emerging capital markets all over the world have a history and Nigeria is not in any way different. The Nigerian capital market represents a small but growing proportion of the nation’s economy. This study on the development of the capital market institution in an emerging economy like Nigeria seeks to examine not only how it came to be established but also how this institution has evolved to impact upon the Nigerian economy. The Nigerian capital market is principally a market for long-term investments where corporate equities and long-term debt securities are issued and traded. It is a market that is regulated by the Securities and Exchange Commission (SEC), which is the apex regulatory body of the Nigerian Capital Market. The capital market is so vital to the development of any economy that no country can risk its existence without putting in place measures to regulate the activities of the market. Consequently, government, at various points in time sought to promote an orderly growth and development of the market for viable investment opportunities. It is against this background that this paper considers the establishment and operation of the Securities and Exchange Commission.