Abstract: A flasher module, installable on a ladder, incorporates multiple high-intensity light-emitting diodes (LEDs), which are coupled to an electro-chemical power source (battery or single cell). The LEDs may be wired for a continuous “ON” condition, but are preferably connected to flasher circuitry. For maximum visible intensity, the flasher circuitry is designed so that all LEDs flash simultaneously about one to two times per second. A first embodiment flasher module is sized to install within the uppermost portion of a ladder rail of C-shaped cross section. A second embodiment module, which provides a larger viewing angle, incorporates the LEDs within a bar that is mountable beneath the uppermost rung of the ladder. Either embodiment of the invention may be equipped with a gravity-actuated switch, which will turn on the flasher circuitry whenever the ladder is deployed at an angle greater than 45 degrees from horizontal.