Abstract: A convertible seat-bed in which a hinged connected seat frame and back frame are supported on a base structure and interconnected by a plurality of articulated control members which coact to control the movement of the seat frame and back frame between a seat forming position in which the seat frame extends generally horizontally and the back frame extends generally in an upright position, and a bed forming position in which the seat frame and the back frame extend horizontally in a generally coplanar relationship, the controlled movements of the back frame being such that the path of movement of the top edge portion of the back frame, during conversion from the seat forming position to the bed forming position and vice versa, is confined to a substantially vertical plane.