Optimally tuning a PID controller is a well-known engineering problem needed in many research fields. In recent years, several approaches for PID controller design were proposed and achieved encouraging results. However, the results are far from ideal state and there is a need to introduce the new approaches or improving the existing methods. We propose a swarm intelligence approach, a self-adaptive differential evolution (SaDE) algorithm for tuning the PID controller. The main objective is to obtain the optimal values of PID variables to enhance the PID's performance indexes. The simulation results on three well-known benchmarks show the superiority of the proposed SaDE compared to other counterparts.