This paper presents some of the fundamental principles involved in missile autopilot design using the well known classical control approaches and allows a guidance engineer to grasp a sound understanding and knowledge in this field. In addition, the paper provides a robust classic controller for stabilizing the guidance system of a beam rider guided missile in addition to satisfying the performance requirements upon miss distance and demanded normal acceleration. The paper presents the analysis using the analytic approach and the simulation of a simple system from which the concluded remarks are applicable to a more general guidance system. The Paper shows the effects of the sampling period, the compensator time constants and the guidance gain upon the system performance. The contribution of the paper stems from the easy presentation of a simple classic controller and showing its effect upon the system performance either analytically cr through system simulation. The results are obtained using the Guidance systems simulation Toolbox, due the author, under the MATLAB environments.