The feasibility of utilizing the fluid energy mill for grinding potassium perchlorate for use in pyrotechnic blends was investigated. It was found that the particle size of the material was significantly reduced by the action of the mill with no significant change in the level of contamination. The grinding parameters selected seemed to have no direct relationship with the physical properties of the final product. The action of the mill induced a significant electrostatic charge on the potassium perchlorate which affects the handling characteristics and possibly the chemical character. The feasibility but not the desirability of utilizing the fluid energy mill to grind potassium perchlorate was demonstrated.