This paper empirically examines depositors' ability to distinguish healthy banks from problematic banks, a necessary condition for depositors to impose discipline on banking institutions. We analyzed a large panel of 784 deposit-taking institutions in Japan during the period from the 1992 financial year to the 2002 financial year. Our estimates indicate that depositors rightly appreciated the difference between healthy banks and risky banks, and that depositors of larger institutions are more sensitive to the bank risks than those of smaller institutions. We further argue that the estimated risk sensitivities of depositors are large enough to discipline the deposit-taking institutions.