Abstract: A quick release fold-up tailgate assembly for attachment to a vehicle having a cargo space defined by a bed, sidewalls, and a tailgate pivotable between open and closed positions with respect to the bed and sidewalls includes a back panel substantially coextensive with the inner surface of the tailgate and a pair of side panels which are pivotable with respect to the back panel on opposite sides of the back panel between a retracted position at which the side panels are parallel to the back panel to fold up the assembly and an extended position at which the side panels are engageable with the sidewalls to extend the cargo space when the tailgate is in its open position. Hinges pivotally attach the side panels to the back panel and the fold-up assembly to the inner surface of the tailgate.