Abstract: A universal bed rail mount for securing bedside rail risers to a mattress supporting bed frame is disclosed. The mount comprises an L-shaped support for embracing the bed frame and is formed of two legs having an opening at an outer portion of each of the legs. The mount also includes at least one tension plate having a hole at a central portion thereof and having bearing surfaces at each of opposite ends of the plate. The bearing surfaces are adapted to be received in the openings in the outer portion of each of the legs. A bolt is received in the tension plate and is adapted to abut the bed frame embraced by the L-shaped support. An adjustable mechanical advantage element is on the bolt and on the tension plate to selectively adjust the position of the bolt in the hole in the tension plate and thereby adjust the tension between the L-shaped support and the tension plate with the bed frame therebetween. A riser guide support is affixed to an exterior surface of one of the legs.