This paper presents an algorithm that can be used to design either conventional or fuzzy logic control systems. In order to use the algorithm, the engineer must first choose a performance index for the system which he or she wants to optimize relative to some specified design parameters. For conventional state space controllers, the design parameters are the feedback constants associated with the state variables of the system. For fuzzy logic controllers, the design parameters are the parameters used to define the fuzzy sets for the input state and control variables. We use the algorithm to design proportional plus derivative (PD) and proportional, integral, and derivative (PID) control systems and their equivalent fuzzy logic control systems. The algorithm therefore provides a unifying approach for designing either conventional or fuzzy logic control systems.