Abstract: A foldable mudflap assembly for retractably disposing mudflaps behind the wheels of a truck or the like comprised of an elongated support member adapted to be attached to the truck between and proximate the truck's wheels, an elongated extension member pivotally connected to each end of the support member such that mudflaps attached to the extension members can be pivotally extended into an operative position behind the truck's wheels or to a retracted position between said wheels. The mudflaps are releasably locked into their extended operative position by providing guide plugs link connected to the extension members and slidable within the support member; a releasable stop member is in turn disposed to engage the guide plug within the support member to prevent axial movement thereof. Simple mating hooks are provided to lock the mud flaps in their fully retracted position.