Abstract: An anti-theft alarm device for fire extinguishers is provided for use in conjunction with a standard-type, portable fire extinguisher. The structure of the alarm device includes a protective, anti-tamper housing with a sound producing device utilizing a bell crank, an actuating spring, and a hold down arm. Disengagement of the bell crank from the hold down arm occurs when the fire extinguisher is removed from its supporting bracket actuates the alarm. The device provides an alarm when an unauthorized taking of a fire extinguisher occurs and helps to locate the stolen extinguisher. Additionally, it serves as a fire alarm in case of a real fire and the fire extinguisher is being properly utilized.