We provide evidence that the impact of the investment horizon of institutional investors on the credit risk of U.S. industrial firms is both statistically and economically significant. Ceteris paribus, a one percent point increase in the ownership by short-term (long-term) institutions leads to a 0.188 (.046) percentage point decrease (increase) of a firm’s credit spread during 2001–2011. However, during the financial crisis period of 2007/08, long-term institutional investors tend to reduce a firm’s credit risk, especially when a firm’s risk profile is high. Hence, long-term institutions play an important role in enhancing financial stability during the crisis period by mitigating risk.