Abstract: A portable, adjustable shelf apparatus comprises a shelf having a front edge, a rear edge and side edges. A back member is fixed to the upper surface of the shelf adjacent the shelf rear edge. Included are first and second elongate, slender shelf-hanging chains, each having first and second end regions. First end regions of each of the first and second chains are secured to an under surface of the shelf adjacent the shelf front edge in a spaced apart relationship. Eye screws are installed into the shelf from the under surface of the shelf adjacent the shelf rear edge. Split rings are included for detachably attaching the second end region of each of the chains to the eye screws to thereby enable the shelf to be hung securely from an upper railing of a balustrade at any desired height. Plastic sleeves are installed over at least regions of the chains to protect railings from which the shelf is hung. Side rails may be installed along front and side edges of the shelf to retain objects on the shelf.