The invention relates to a device for controlling the suspension of the body shell of a motor vehicle. According to the invention, the device comprises: a means (21) for calculating a set modal stress (F1) for the shock absorber as a function of at least one absolute modal body shell speed (V.sub.mod), a means (34) for calculating a set modal stress (F2) for the shock absorber as a function of a relative modal body shell speed (V.sub.mod2) in relation to the mid-plane of the wheels, a means (22) for detecting a bias on the vehicle, and a means (23) for calculating a weighting coefficient .alpha. for calculating a set modal stress (F) for the shock absorber using formula F=(1-.alpha.)F1+.alpha.F2.