Abstract: A replacement seat and back is disclosed for installation onto an existing chair which includes a unitary molded construction with a seat supporting a substantially upright back joined by an integral curved portion. The back is provided with a hollow interior with a slotted entrance adjacent to the curved portion so as to insertably receive the back of the existing chair. The seat includes an edge marginal downwardly depending attachment flange constituting a snap-on attachment for securing the seat to the existing seat. Preferably, the contour, color and overall shape of the replacement seat and back conforms with the contour, color and overall shape of the existing chair.