Abstract: A shelf bracket, particularly adapted for mounting on railings and the like, comprises a mounting bracket formed in a generally inverted U-shape with first and second legs depending from ends of a transverse segment. An elongate rigid shelf supporting member is fixed to lower regions of the first leg, below the lower end of the shorter second leg, to project orthogonally outwardly away from the second leg. A thumbscrew is installed in the first leg, below the shelf supporting member for engaging a railing support and enabling leveling of a shelf supported by two or more brackets below the level of the railing. A second thumbscrew is provided in the second leg, relatively close to the transverse segment, for adapting the bracket to railings more narrow than the length of the transverse segment and for clamping the bracket to the railing. Locking nuts are provided for each thumbscrew to maintain the adjustments.