Abstract: An aerodynamic enclosure for a refrigerated trailer. The enclosure fits over the upper portion of the front wall of the trailer, enclosing the factory installed refrigeration unit and motor. The enclosure has an upper front opening which fits around the air opening of the refrigeration equipment. A second front opening is covered with hinged doors to provide access to the refrigeration equipment. A pair of side openings are covered by hinged doors and provide access to the refrigeration controls and equipment. A top opening provides an outlet for air from the enclosure. The enclosure is symmetrical about its vertical axis and is aerodynamically contoured to reduce wind resistance and provide substantial economies in fuel consumption. An auxiliary door may be used to cover the upper front opening of the enclosure when the refrigeration equipment is not in use.