Abstract: An improved retractable fold-up and extensible trailer typically for towing behind automotive vehicles, wherein the respective load accommodating sections of the trailer are interfittable and foldable into a compact configuration for storage and are extensible to form an enlarged trailer or bed for use. Essentially the trailer bed is in three sections, a center section attached to a wheel and axle assembly, and forward and rearward sections hingedly connected thereto. Latches are provided to retain the sections in either folded or unfolded positions, and a retractable tongue is provided on the front section for towing. The trailer may have nesting side portions or may be adapted to accommodate removable sides constructed in conventional stake body form.