The present invention relates to an agrochemical composition containing a pesticide and a copolymer, which contains in polymerized form at least 20 wt % vinylimidazol and/or a quaternized vinylimidazol, an acidic comonomer, and a hydrophobic comonomer, which comprises C1-22 alkyl (meth)acrylate, mono C1-22 alkyl terminated poly(ethylene glycol) (meth)acrylate, vinyl ester of aliphatic C1-32 carboxylic acids, or vinyl C1-4 alkyl ether. It further relates to a method for preparing said composition by mixing the pesticide and the copolymer; and to a use of said copolymer as dispersing agent in a composition containing a pesticide. In addition it relates to a method for controlling phytopathogenic fungi and/or undesired plant growth and/or undesired attack by insects or mites and/or for regulating the growth of plants, where said composition is allowed to act on the particular pests, their habitat or the plants to be protected from the particular pest, the soil and/or on undesired plants and/or the useful plants and/or their habitat. Finally, it relates to seed containing the said composition.