A fall safety barrier for use around a hole, comprising: (a) anchor means (20, 22) removably secured adjacent a perimeter of the hole, (b) first collapsible barrier means pivotally mounted about a first pivot location of the anchor means (20, 22), (c) second collapsible barrier means pivotally mounted about a second pivot location of the anchor means (20, 22) opposite the first location, (d) means for allowing the first collapsible barrier means to pivot between a first contracted position, where it lays upon the second collapsible barrier means, and a first expanded position, where it is upright and forms a first side of the fall safety barrier, (e) means for allowing the second collapsible barrier means to pivot between a second contracted position, where it lays adjacent the anchor means, and a second expanded position, where it is upright and forms a second side of the fall safety barrier opposite the first side, (f) first linking barrier means located between adjacent first ends of the first and second collapsible barrier means and forming a third side of the fall safety barrier, and (g) second linking barrier means located between adjacent second ends of the first and second collapsible barrier means and forming a fourth side of the fall safety barrier opposite the third side, wherein the first and second collapsible barrier means each comprise mesh gates (32, 34), characterized in that the first and second linking barrier means each comprise one or more chains (46, 48) that extend between adjacent ends of the mesh gates (32, 34) and further including strut rods which support the first and second collapsible barrier means in their respective expanded positions, the strut rods (36a, 36b, 36c, 36d) being pivotally connected at first ends thereof to the anchor means (20, 22) and removably connected at second ends thereof to opposite sides of each gate (32, 34) and further including brace rods (30, 31) which are pivotally mounted to a top flange of the first collapsible barrier means, and means for allowing the brace rods (30, 31) to pivot between a third contracted position, where the brace rods (30, 31) lay against the first collapsible barrier means, and a third expanded position, where the brace rods (30, 31) extend crosswise and interconnect the top flanges (33, 35) of the first and second collapsible barrier means, wherein the fall safety barrier is assembled around the hole by the steps of pivoting the first collapsible barrier means from the first contracted position over the hole to the first expanded position so that the brace rods (30, 31) are in the third contracted position, connecting the second ends of a first pair of the strut rods (36a, 36b) so that they support the first collapsible barrier means in the first expanded position to form a first side of the assembled fall safety barrier, pivoting the second collapsible barrier means from the second contracted position over the hole to the second expanded position, whereby the first and second linking barrier means are elevated to form third and fourth sides, respectively, of the assembled fall safety barrier, simultaneously with the pivoting of the second collapsible barrier means to the second expanded position; and connecting the second ends of a second pair of the strut rods (36c, 36d) so that they support the second collapsible barrier means in the second expanded position to form a second side of the assembled fall safety barrier, and pivoting the brace rods (30, 31) to the third expanded position. (a) anchor means (20, 22) removably secured adjacent a perimeter of the hole, (b) first collapsible barrier means pivotally mounted about a first pivot location of the anchor means (20, 22), (c) second collapsible barrier means pivotally mounted about a second pivot location of the anchor means (20, 22) opposite the first location, (d) means for allowing the first collapsible barrier means to pivot between a first contracted position, where it lays upon the second collapsible barrier means, and a first expanded position, where it is upright and forms a first side of the fall safety barrier, (e) means for allowing the second collapsible barrier means to pivot between a second contracted position, where it lays adjacent the anchor means, and a second expanded position, where it is upright and forms a second side of the fall safety barrier opposite the first side, (f) first linking barrier means located between adjacent first ends of the first and second collapsible barrier means and forming a third side of the fall safety barrier, and (g) second linking barrier means located between adjacent second ends of the first and second collapsible barrier means and forming a fourth side of the fall safety barrier opposite the third side,