Abstract: A lighted guide assembly for boat trailers used in centering a boat on a trailer during the loading and unloading process. The lighted guide post assembly provides running and braking lights for the trailer that can be seen from the rear of the boat trailer despite the height or length of a trailered boat. The lighted boat guide post assembly has first and second uprights each formed from a partially or substantially transparent tube with directional lights placed therein. The lighted boat guide post is electrically coupled to the boat trailer towing vehicle and provides lighting that extends from the trailer frame to the top of each guide post.