A passenger seat assembly for a vehicle, particularly an aircraft, which is adapted to provide self-contained, individual seating and sleeping accommodation for a passenger, said seat assembly comprising: supporting structure (42) for supporting said assembly off the floor of a vehicle; one or more movable passenger-bearing, structural components (71,72); and means for connecting said movable, structural components to said structure such that said components can be selectively moved between a seat configuration, in which a plurality of passenger-bearing surfaces on said one or more structural, movable components (71,71) or said supporting structure form a seat for the passenger, and a bed configuration, in which a plurality of said bearing surfaces (47,48,67,74,76) are disposed substantially coplanarly and substantially contiguously to form a bed for the passenger; characterised in that at least one of said movable components (72) is double-sided, comprising first and second opposite sides, one of said sides having a first seat surface (73) that forms part of the seat in said seat configuration, and the other side having a second bed surface (74) that forms part of said bed in said bed configuration.