This paper discusses the proportional-integralderivative control scheme for a twin rotor multiple input multiple output system (TRMS), which is a nonlinear system with two degrees of freedom and cross couplings. The objectives of the work are to stabilize the TRMS, to attain a particular position and to make it to track a trajectory. Four PID controllers are used for achieving the objectives. The parameters of the PID controllers are tuned using the real valued genetic algorithm (RGA). The initial search range of the RGA is obtained using a control design optimization (CDO) technique. The control scheme is initially implemented for the decoupled system viz., horizontal and vertical 1-degree of freedom (1-DOF) systems, using 1 PID controller for each system, and it is followed by the implementation of the control scheme for the 2-degree of freedom (2-DOF) System.