Many controller realizations are structurally constrained. Some typical examples are static output feedback, constant gain feedback for multiple operating points of a system, two-controller feedback, and decentralized feedback. A general class of problems of regional pole placement of multivariable systems with such control structure constraints is considered and a unified numerical method is given to solve them, First a problem in this class is converted to a problem of solving a system of equalities and inequalities, This system is then solved by using a modified homotopy method.