This study examines the impact of top management changes on stock returns in Nigeria from 1997 to 2005. The study also reflects on the impact of board composition and politics on shareholders wealth. The test of shareholder wealth effects around the time of top management changes is structured as an event study. Data were obtained principally from the Lagos and Ibadan branches of the Nigerian Stock Exchange (NSE) and the Securities and Exchange Commission (SEC). The study concludes that change in top management, including the composition of the board of directors, matters because announcements of board changes contribute to shareholder wealth, while corporate leaders affect the performance of the organization. In Nigeria, the announcement of the appointment of politically connected top managers produces positive information content and positive investor reaction, while the announcement of top management changes without political connections results in negative shareholder wealth. The findings are consistent with hypothesized benefits from internal mechanisms of corporate control in management change.