In this paper, one of the most current new stochastic optimization method is proposed to tune decentralized proportional-integral-derivative (PID) controller for a multi-input-multi-output (MIMO) system. PID controller is still the most used controller in industrial application due to its easy application in control system. However, it still having problem to be tuned correctly especially for MIMO system. The decentralized controllers in this paper will be tuned simultaneously using duelist algorithm (DA) method and optimal value of controller parameters is obtained from a minimum of integral absolute error (IAE) value. The optimization of the objective function is based on the evaluation of IAE when a step change in u1 and u2 is introduced to the system. Form the simulation result, the proposed method is observed to have a better performance than other popular tuning method. © Published under licence by IOP Publishing Ltd.