A tilt mechanism (10) for a chair comprises a base (11), a back bracket (12) configured to support a chair back (4) and a coupling arrangement (16, 25) configured to couple the back bracket (12) to the base (11). The coupling arrangement comprises a guide track (25) and a guide member (16). One of the guide track (25) and the guide member (16) is provided on a portion of the back bracket (12) extending from a back attaching portion (23) to a pivot coupling portion (24) at which the back bracket (12) may be articulated to a chair seat (3). The other one of the guide track (25) and the guide member (16) is provided on the base (11). When the coupling arrangement (16, 25) couples the back bracket (12) to the base (11), pivoting the back bracket (12) about the pivot coupling portion (24) causes the guide member (16) and the guide track (25) to be displaced relative to each other, effecting a displacement of the pivot coupling portion (24) relative to the base (11).