A toilet seat assembly comprising a seat (2) and hinge means (5) for hingedly attaching the seat (2) to a toilet. The hinge means (5) comprises a mounting block (50) having an arcuate slot (17), and an arcuate seat tang (20) extends rearwardly of the seat which is slidable in the arcuate slot of the mounting block. The assembly may also comprise a lid (3); and hinge means for hingedly attaching the lid (3) to a toilet; and an arcuate lid tang (23) extending rearwardly of the lid which is also slidable in the arcuate slot (17) of the mounting block (50).