A dropout detecting apparatus includes a high-frequency-range compensation circuit for emphasizing a signal component in a high-frequency-range of a reproduced high-frequency signal, a reference signal generating circuit for deriving a reference signal from the reproduced high-frequency signal. The reference signal has an inverse relationship to the reproduced high-frequency having the emphasized signal component supplied from the high-frequency-range compensation circuit. The apparatus further includes a pulse signal generating circuit for converting the reproduced high-frequency signal supplied from the high-frequency-range compensation circuit into a pulse signal on the basis of the reference signal supplied from the reference signal generating circuit, and a circuit for determining whether the reproduced high-frequency signal includes a dropout on the basis of a change in period of the pulse signal supplied from the pulse signal generating circuit and for outputting a dropout detection signal.