Abstract: A boat trailer washing system is used after a trailer has been immersed in a body of water to cleanse the same from any salty residue which will easily and quickly have a detrimental effect on the structure of the trailer. The frame of the trailer has longitudinal water pipes installed thereon which carry a multiple of nozzles directed to the frame in one direction. The trailer hitch has a water tank mounted thereon which is the source of water for a pump located on the trailer. When the pump is activated, it will draw water from the water tank, pressurize the water and deliver the water under high pressure to the nozzles located on the water pipes. The water pipes may be rotated so that the water pressure may be directed to a hull of a boat located on the trailer.