This paper deals with the control of semi-active automotive suspensions using H∞ state-space optimization techniques. After the derivation of two standard models of the system, quarter car and half car model, three H∞ controllers are developed in the fully active case and then adapted to the non-linear real system using a sort of clipped control. The first controller is focused on ride comfort optimization, the second on both comfort and handling improvement, the third is a global controller derived from half car model. Performance indices related to ride comfort and drive safety are introduced to evaluate the proposed controllers. Simulations are performed to show that semi-active controlled suspensions succeed in achieving higher levels of ride comfort and drive safety with respect to a passive setting.