Abstract: A brake-light/hazard-warning board structure includes a first bar, a second bar, a third bar each having a pivot member at distal ends thereof, and three connecting units for connecting pivot member of said first, second, and third bars and providing a pivotal relationship therebetween. A slot is formed in one of the pivot member and the connnecting unit for receiving a suction cup by which said brake-light/hazard-warning board structure is releasably mounted to a vehicle when used as a brake light. A number of light emitting diodes are provided on the first, second, and third bars and are electrically connected in series, with two terminals electrically connected with a power source.