The viscosity of aqueous dispersions of normally solid organic peroxides may be advantageously lowered through the use of surfactants which are polyglyceryl esters of C6-C12 fatty acids. The reduction in viscosity facilitates milling the peroxides to reduce particle size and also provides dispersions of small particle size peroxides which may be readily poured or pumped. The aqueous dispersions are useful as components of pharmaceutical, personal care, and cleaning products and the like and are effective decolorizing agents for food products, industrial products and the like.