A wheelchair suspension system includes a suspension member which clamps to longitudinal bars of the wheelchair frame located below the seat of the wheelchair. The suspension member is elongate with upper and lower parallel leaf springs extending between the opposing ends of the suspension member. An axle support member is hinged to each end of the suspension member, by pivotal connection to each of the leaf springs. Each axle support member receives the axle of one of the opposing large rear wheels of the wheelchair. As the large wheels encounter uneven areas on the ground surface on which the wheelchair moves, the leaf springs flex reducing vibrations and shock to the wheelchair occupant. The axle support members maintain their generally upright orientation as the leaf springs flex so that camber angle of the rear wheels does not change.