In a vehicle suspension system including a hydraulic actuator between a sprung mass consisting substantially of a vehicle body and an unsprung mass consisting substantially of a wheel, a force proportional to but opposite in phase to an inertia force acting on the unsprung mass is applied by the actuator to the unsprung mass so that the ability of the tire to maintain contact with the road surface may be improved. This produces very little effect on the behavior of the sprung mass, but the vehicle handling is significantly improved. Better contact with the road surface not only improves the vehicle handling but also reduces the consumption of energy by the hydraulic actuator. A particularly favorable result can be obtained when the hydraulic actuator further applies a damping force proportional to the absolute velocity of the sprung mass to the sprung mass.