An optimization procedure is developed for controls/structures interaction using a multiobjective formulation. A rotating composite cantilever box beam model is presented which includes piezoelectric strain actuators for vibration control. The model is implemented using the finite-element method. Multiple design objectives are efficiently combined using the Kreisselmeier-Steinhauser function approach. Actuator locations and ply stacking sequences are represented by discrete (0,1) variables while structural/control parameters such as box beam dimensions are continuous design variables. A transformation technique is used to formulate the combined continuous/discrete problem as a purely discrete problem. This allows both optimal actuator locations and structural/control parameters to be determined inside a closed loop procedure. A technique based on simulated annealing is used for optimization in conjunction with an approximate analysis procedure to reduce computational effort.