Abstract: A protective railing assembly for an elevator shaft door opening includes a railing which is secured to the floor at the shaft door opening by two hinged parallelogram linkages. The protective railing can be moved between two different horizontally spaced positions and thus be displaced through a predetermined distance without being removed from the shaft door opening. The railing can be mounted while the shaft door opening is still barricaded to permit the barricading to be removed and a shaft door mounted. The railing provides a continuous protection against the falling of persons into the shaft during the shaft door assembly. The protective railing is extensible for adaptation to different opening widths and the parallelogram linkages are maintained at a constant spacing one from the other to permit installation in openings of different widths.