The invention relates to seed treatment compositions comprising activeingredient, polyarylphenol polyalkoxyether phosphate and/or polyarylphenol polyalkoxy ether sulphate, and copolymerhaving polyalkoxy ether side chains. Thepolyarylphenol polyalkoxy ether phosphate and/or the polyarylphenol polyalkoxyether sulphate in combination with the copolymerhaving polyalkoxy ether side chains are used as dispersant, especially toprovide a dispersion of suspended active ingredient. Thepresent invention also relates to methods of treating seed with such acomposition.