Abstract: An outrigger is designed to be used at the corner of a scaffold in generally cantilever-like fashion to underlyingly support what would normally be free projecting ends of horizontal planks projecting outboard or endwise of the scaffolding and thereby permit a worker to safely stand outboard endwise of the scaffolding, the outrigger including a pair of generally spaced parallel first and second arms each having inboard and outboard ends with a hook-like element at each inboard end to secure the outrigger by either arm to a corner of the scaffold, and the first and second arms being supported in cantilivered and extensible fashion from each other to accommodate the outrigger for varying distances between an associated scaffold buck and the work surface which is located endwise therefrom.