An aqueous emulsion composition of organic peroxide, including from 10 to 65% by weight of one or a plurality of organic peroxides, from 2 to 25% by weight of at least one antifreeze agent, from 0.01 to 10% by weight of at least one emulsifying agent, optionally at least one additive, water, of which the quantity is defined in order to form the remainder of the total composition (100%), wherein the emulsifying agent is a colloid agent of a polyvinyl acetate having a degree of hydrolysis greater than 80% and a viscosity, measured in solution in water at 4% by weight at 20° C., less than or equal to 5 mPa·s, said viscosity being measured with a Brookfield RVT viscometer, needle no. 3, 20 rpm, in accordance with the ISO 2555 standard. Also, to the method of preparing same and the use thereof.