Abstract: A rail clamp is provided for attachment to a vertical rail such as a side rail of a ladder as are used on the rear of recreational vehicles. The rail clamp is molded from plastic and includes threaded members with knobs which allow the clamp to be tightened in any of a variety of positions along the rail. A pair of rail clamps are generally used for carrying bulky items such as lawn chairs exteriorly of the RV. The rail clamps are molded from durable plastic and will fit different size ladder rails as required. The knobs, threaded members and securing nuts can be reversed for convenience in use to either the right or left sides of the clamp body portion.