An adjustable shelf assembly for displaying product. The shelves can be oriented in horizontally or in a forward sloping position with a simple adjustment. The shelves are generally rectangular and comprise upper and lower mounting pins located on each side of the shelf, extending downwardly from the rear edge of the shelf. The mounting pins are vertically spaced and slightly offset from one another. The mounting pins are used to mount the shelf on a support frame comprising a plurality of openings along the vertical members of the frame. The upper mounting pins are placed in first openings along the frame. The lower mounting pins are positionable either flush against the front surface of the vertical members to position the shelf in a horizontal orientation or inside second openings along the frame to position the shelf in a forward sloping orientaion.