Grinding circuit should provide stable particle size distribution while operating in a way to maximize mill efficiency. In this paper, a fuzzy logic-based supervisory control strategy is proposed for controlling product particle size while improving mill efficiency in a ball mill grinding circuit. In the supervisory level, fuzzy logic-based control determines the optimized setpoints of the regulatory level controllers. The whole system ensures a long-term stableness of product quality while increasing the mill efficiency more than six percent in practical industrial application in comparison with conventional control. The results of the practical industrial operation demonstrate the feasibility, reliability and effectiveness of the proposed control strategy.