A study into the effects of wall compliance on boundary layer flow in an adverse pressure gradient has been undertaken. The two-dimensional flow given by a Falkner–Skan profile was considered where a powerfulinviscidinstability mechanism occurs as a result of a point of inflexion in the boundary layer profile. Results are presented for two cases: (a) a purely inviscid calculation where the compliant wall is modelled as a thin plate supported by a spring foundation, (b) a double-layer viscoelastic wall model with viscous effects retained. Wall parameters which ensure the absence of hydroelastic instability were used and found to produce growth rate reductions in excess of50&percent;of the corresponding rigid wall values. ©1997 American Institute of Physics.