Abstract: A wheelchair seat and back construction adapted to be removably mounted upon a conventional wheelchair frame. A chair base with seat and back member secured thereto is mounted to a chair support by springs positioned between the base and support with the support secured to the wheelchair frame such that the wheelchair user can rock in the chair by reason of the spring mounting between the chair support and chair base. Front and rear lock levers are provided to selectively secure the chair base with seat and back member attached relative to the wheelchair frame to maintain the seat and back in rigid, unrocking condition. The seat and back members are hingedly connected to each other with the seat member being slidably movable upon tracks mounted to the chair base to permit the back member to move into a reclining position for the user upon movement of the seat member.