Abstract: A shelf assembly comprises flat base panels, side panels and back panels adapted to be assembled into a unitary structure. The base panel has connecting ledges extending from one edge of the base panel to the center line thereof. The front faces of adjacent connecting ledges have, respectively, complementary pegs and holes. The lateral surfaces of adjacent connecting ledges are provided with complementary pegs and oblong holes to permit sliding engagement thereof. The side faces of the connecting ledges and the back portions of the base panels are provided with holes to receive pegs extending from the back and side panels. Sliding engagement of corresponding connecting ledges cooperates with the peg and hole connections to provide a statically stable, torsion resistant assembly without the use of additional mechanical fastening devices.