A battery operated moisture indicator for selective attachment to an existing diaper worn by a baby, having an audible alarm and having a liquid crystal display bulb, for providing an audible alert and a visual alert, respectively, when the diaper has been wet by the baby. The circuit includes a mechanism for selectively activating the alarm and the liquid crystal display bulb when an aqueous electrolyte-containing solution has wetted the diaper. The moisture indicator is provided with a diaphanous sac having a clip for selectively attaching the moisture indicator to the external surface of the front of an existing diaper, thereby providing a moisture indicator that is comfortable for a baby to wear.