Abstract: A truck bed height extension assembly for a pickup truck includes a truck bed and a pair of side panels. The truck bed includes a floor and a pair of spaced apart sidewalls. Each of the pair of spaced apart sidewalls includes an exterior wall, an opposite interior wall, and an elongated cavity positioned between the exterior wall and the interior wall of each of the pair of sidewalls. The pair of side panels are linearly displaceable in a vehicle vertical direction between a retracted position and an extended position. In the retracted position, each of the pair of side panels are positioned within the elongated cavity defined in each of the pair of sidewalls. In the extended position, each of the pair of side panels are positioned to extended at least partially outside of the elongated cavity of each of the pair of sidewalls.