A flash monitor alarm system is provided for detection of emergency vehicle flashers or for detection of flashes in photography. For emergency flasher detection the unit is positioned in a vehicle within a direct line of sight of potential emergency flashers. When emergency flashers are detected, an alarm is activated to warn the vehicle's occupants. For a photographic monitor alarm system, a detector is inductively coupled to a flash tube assembly's flash tube or tube power cable for activating a pulsating flash monitor indicator perceptible to the photographer when the flash tube has properly fired. The flash monitor alarm system includes flash monitor electronics and a power source, both of which are built into a compact housing.