Abstract: The present invention provides a door restrictor apparatus for locking and preventing a sliding door on an elevator car from unauthorized opening. The door restrictor apparatus includes a locking lug mounted on the elevator car, an actuating mechanism having an actuating surface that moves toward and away from a surface on the car door, and a pivotable hook, having an axis of rotation perpendicular to the direction of the door movement is mounted on the door. The hook has a beak end that alternatively passes by or engages the locking lug. The movement of the actuating surface is coupled to the rotation of the pivotable hook by a crank and push rod assembly so that the motion of the actuating surface toward or away from the surface of the car door causes the hook to rotate and vice-versa. A means for biasing the restrictor apparatus is provided to urge the actuating surface to move away from the surface of the door and to urge the pivotable hook to rotate in a first direction.