Abstract: A tray holding device for mounting to a D-rung ladder is disclosed. The mounting shaft inserts into an outwardly facing D-shaped aperture of the ladder and slidably engages the inner wall of the rung. In one embodiment, the shaft is D-shaped and fits telescopically within the D-rung opening. Optionally, the shaft is molded in a slightly bowed condition and, when in use, is under flexural tension. Alternatively, molded into the thermoplastic tray-holding portion is an extruded metal shaft. The shaft configurations shown engage the interior wall of the rung cavity and preclude rotation. Some shaft configurations engage both the flat side and the curved side of the D-rung cavity and enable the tray holding device to be reversibly insertable into a rung cavity.