Abstract: A key security device includes a rigid housing with an internal latching device to releasably secure a key within an open keyway formed in the housing. Circuitry is provided along with the latching device to supply an audible or otherwise detectable signal that is initiated following removal of the key and passage of a predetermined timed interval following removal of the key from the housing. Circuitry within the housing responds to insertion and removal of the key to produce an indentifiable alert signal after a determined time interval that may be initiated in response to removal of the key from the keyway. The time interval is reset and the alert signal is cancelled as the key is received in the keyway. An override is provided for the timer and may be operated to selectively extend the time interval and thereby delay operation of the alarm.