Proportional-integral-derivative(PID) control algorithm has the property of simplicity and practicability, but it is difficult to be tuned to control a complex nonlinear system. An advanced particle swarm optimization (PSO) was used to optimize the PID controller for controlling chaotic systems. Computer simulation of its application to several chaotic systems has been done. The controlled chaotic systems are the Hénon chaos, Duffing chaos, six-roll UC mill chaos, Nagumo-sato neuron chaos, Chen's chaos, and permanent magnet synchronous motor chaos. Th chaos control simulation results show that: 1) The output feedback based PID control for chaotic systems is effective; 2) using PID to control complex chaotic systems is feasible; and 3) using PSO to optimize the PID parameters for chaos control is effective and simple in programming.