An access panel assembly for providing access to the interior of a wall is disclosed. The panel is made of a molded plastic, such as a styrene polymer. The door is press-fit and is held in the frame by grooves in the frame which align with resilient proturbences on the door panel. A hidden hinge, which allows the door to be hinged or removed from the frame, is provided. A pair of eccentric cavities serves to provide pivot points for the hinge and engage with hinge pivots on the access door. In this hinge, the pivot point may vary, thereby preventing jamming of the door. A notch is formed in the eccentric cavity to allow removal of the door. Pry holes are provided to assist in removal of the door. An embodiment is disclosed which permits the hinged door to be flush mounted from either side of the frame.