Abstract: An alarm device for detecting moisture in a baby's diaper includes a housing having a moisture detector and a buzzer on the outer surface thereof. A space is provided within the housing, and a circuit board disposed in such space has an electronic circuit and a battery thereon. The electronic circuit is electrically connected to the moisture detector, the buzzer and the battery, and actuates the buzzer when the moisture detector indicates moisture is present in the diaper. Tie-rings are preferably provided on the housing for securing the alarm device to the baby's diaper.