Abstract: A roller shutter is described which has a roller (13) arranged with its axis vertical, so that the shutter curtain (10) is extended laterally in use. The weight of the curtain (10) is supported in the extended condition from a top track (14) having internal running surfaces (35) co-operating with roller wheels (34) of a top chain (29), to which the articulated laths (11) of the curtain are, in turn, attached. Constant tensioning means (18-25) are provided for the curtain, which can follow a straight, angled or curving path. The bottom chain (9) of the curtain may have depending skirts (42), interfitting (at 43, 45) to reduce fire penetration. A lead-in guide (50) of the roller housing (12) has a lifting ramp (53) co-operating with ball glides (38) of the bottom chain to lift the curtain (10) gently onto, and off, the top track (14) running surfaces (35) on leaving and re-entering the housing (12).