In this study, an active suspension for combined ride comfort and attitude control of a vehicle equipped with hydro-pneumatic (HP) suspension system is developed. The state-dependent Riccati equation (SDRE) control is employed in the design of the active suspension controller. A detailed sensitivity analysis is performed to examine the effects of the selection of weighting coefficients on the ride comfort and attitude control. According to the results of the sensitivity study, three different sets of fixed weighting coefficients and a fourth set with adaptive weighting coefficients are developed. The adaptive weighting coefficients are implemented by the state constraint in the SDRE formulation. The controller is tuned mainly for ride comfort at low suspension deflections and for keeping the proper vehicle attitude at higher suspension deflections. Simulation results show that the active suspension with the adaptive weighting is successful in improving both ride comfort and the vehicle attitude.