Abstract: A portable case for storing an orthodontic retainer. The case includes a movable cover that provides access to the interior of the case. A switch mounted within the case actuates a timer circuit when the retainer is disposed within the case and the cover of the case is closed. After the retainer is placed within the container and the cover is closed, the timer begins counting. When a preset period of time has elapsed, the timer actuates an audible signal generator. Upon actuation, the audible signal generator generates a pulsed audible signal such as a beep. The audible signal is preferably generated periodically, with progressively shorter intervals between audible signal pulses. The audible pulses serve to remind the owner to replace the retainer in his or her mouth after eating. Further, in the event that the case is misplaced, the audible signal can be used to locate the retainer case.