Abstract: A protective skirt for an open frame trailer adapted to transport vehicles. The trailer includes a wheeled chassis supporting a frame and track assembly. The trailer has a front-end adapted to be mounted in towing engagement on a tractor truck, a rear end adapted for receiving vehicles to be carried, and a middle section including the frame and track superstructure for supporting the vehicles. The protective skirt includes a pair of first skirt sections mounted one on each side of the chassis in screening position at the trailer front end, a pair of second skirt sections mounted on the chassis one on each side thereof in screening position at the trailer middle section, a pair of third skirt sections mounted in screening position one on each side of the chassis above the wheels, and a pair of fourth skirt sections mounted on the chassis one on each side in screening position at the trailer rear section. The skirt assembly protects vehicles carried on the trailer against damage from rocks and road debris.