This study examines how the investment horizon of the institutional shareholders of a firm affects the stock performance of private equity placements. The results show that firms with long-term institutional investors receive significantly positive abnormal returns around the offering announcement. Post-issue stock price underperformance is especially pronounced in firms held by short-term institutional investors. These findings suggest that private placement firms with long-term institutional investors acquire certification and monitoring-related benefits and thus reduce the information asymmetry and entrenchment costs between managers and external investors.